diff --git a/pythonlings/app.py b/pythonlings/app.py
index 8023d0b..68ee35c 100644
--- a/pythonlings/app.py
+++ b/pythonlings/app.py
@@ -28,11 +28,16 @@ def __init__(
         self._force_picker = force_picker
 
     def on_mount(self) -> None:
+        first_launch = not self.state.seen_intro
         self.push_screen(TopicPickerScreen())
         target = self._startup_target()
         if target is not None:
             topic, exercise = target
             self.push_screen(TrackScreen(topic, start_exercise=exercise))
+        if first_launch and target is not None:
+            from pythonlings.screens.welcome import WelcomeScreen
+
+            self.push_screen(WelcomeScreen())
 
     def _startup_target(self) -> tuple[str, str | None] | None:
         if self._start_topic is not None:
diff --git a/pythonlings/core/state.py b/pythonlings/core/state.py
index 83732a0..5a686d0 100644
--- a/pythonlings/core/state.py
+++ b/pythonlings/core/state.py
@@ -4,6 +4,7 @@
 
 import json
 import sys
+from collections.abc import Iterable
 from dataclasses import dataclass, field
 from pathlib import Path
 
@@ -84,3 +85,12 @@ def next_pending(exercises: list[Exercise], completed: set[str]) -> str | None:
         if ex.name not in completed:
             return ex.name
     return None
+
+
+def completed_count(exercise_names: Iterable[str], completed: set[str]) -> int:
+    """How many of `exercise_names` are completed.
+
+    Counts only names that exist in the curriculum, so stale `completed`
+    entries (e.g. exercises renamed or removed) cannot inflate the total.
+    """
+    return sum(1 for name in exercise_names if name in completed)
diff --git a/pythonlings/pythonlings.tcss b/pythonlings/pythonlings.tcss
index 47d6091..c431d7b 100644
--- a/pythonlings/pythonlings.tcss
+++ b/pythonlings/pythonlings.tcss
@@ -121,3 +121,30 @@ DocsScreen {
     height: 1;
     color: $text;
 }
+
+WelcomeScreen {
+    align: center middle;
+}
+
+#welcome-window {
+    width: 72%;
+    max-width: 76;
+    height: auto;
+    padding: 1 2;
+    border: heavy $primary;
+    background: $surface;
+    color: $text;
+}
+
+#welcome-title {
+    height: 1;
+}
+
+#welcome-body {
+    margin: 1 0;
+}
+
+#welcome-footer {
+    height: 1;
+    color: $text-muted;
+}
diff --git a/pythonlings/screens/track.py b/pythonlings/screens/track.py
index bb0332f..fc303c1 100644
--- a/pythonlings/screens/track.py
+++ b/pythonlings/screens/track.py
@@ -10,7 +10,7 @@
 
 from pythonlings.core.exercise import Exercise, RunResult
 from pythonlings.core.runner import run as run_exercise
-from pythonlings.core.state import next_pending, save as save_state
+from pythonlings.core.state import completed_count, next_pending, save as save_state
 from pythonlings.widgets.editor_pane import EditorPane
 from pythonlings.widgets.exercise_tree import ExerciseTree
 from pythonlings.widgets.output_panel import OutputPanel
@@ -19,6 +19,17 @@
 _DEBOUNCE_SECONDS = 0.6
 
 
+def celebration_message(total: int) -> str:
+    """Message shown when every exercise in the curriculum is complete."""
+    return (
+        f"🎉  You finished all {total} pythonlings exercises! 🎉\n\n"
+        "That's the whole curriculum — nicely done.\n"
+        f"Share it: \"I just completed all {total} pythonlings Python exercises 🎉\"\n"
+        "If pythonlings helped, a ⭐ on GitHub or a contribution is hugely appreciated.\n\n"
+        "Press Ctrl+Q to quit, or F4 to revisit topics."
+    )
+
+
 class TrackScreen(Screen[None]):
     """One topic's linear track: editor + output + auto-save loop."""
 
@@ -82,7 +93,13 @@ def _initial_exercise(self) -> str | None:
     def _render_state(self) -> None:
         exs = self._exercises()
         done = sum(1 for ex in exs if ex.name in self.app.state.completed)
-        self.query_one(ProgressBar).update_progress(done, len(exs))
+        all_exercises = self.app.manifest.exercises
+        overall_done = completed_count(
+            (ex.name for ex in all_exercises), self.app.state.completed
+        )
+        self.query_one(ProgressBar).update_progress(
+            done, len(exs), overall_done, len(all_exercises)
+        )
         self.query_one(ExerciseTree).render_topic(
             self.topic, exs, self.app.state.completed, self.current
         )
@@ -175,9 +192,15 @@ def _apply_result(self, exercise: Exercise, result: RunResult) -> None:
         self._render_state()
         if self.current is None:
             self._record_resume(None)
-            self.query_one(OutputPanel).show_final(
-                f"Topic '{self.topic}' complete — press F4 for topics."
-            )
+            all_exercises = self.app.manifest.exercises
+            if next_pending(all_exercises, self.app.state.completed) is None:
+                self.query_one(OutputPanel).show_final(
+                    celebration_message(len(all_exercises))
+                )
+            else:
+                self.query_one(OutputPanel).show_final(
+                    f"Topic '{self.topic}' complete — press F4 for topics."
+                )
             return
         self._load_current()
         self._run_current()
diff --git a/pythonlings/screens/welcome.py b/pythonlings/screens/welcome.py
new file mode 100644
index 0000000..f043285
--- /dev/null
+++ b/pythonlings/screens/welcome.py
@@ -0,0 +1,45 @@
+# pythonlings/screens/welcome.py
+from __future__ import annotations
+
+from textual.app import ComposeResult
+from textual.binding import Binding
+from textual.containers import Vertical
+from textual.screen import ModalScreen
+from textual.widgets import Static
+
+from pythonlings.core.state import save as save_state
+
+
+def welcome_text() -> str:
+    """The first-launch explainer for the edit/save/advance loop."""
+    return (
+        "You learn Python here by fixing small broken programs. The loop is:\n\n"
+        "  1. Edit the current exercise in the built-in editor.\n"
+        "  2. Save -- the check reruns automatically as you type.\n"
+        "  3. Remove the `# I AM NOT DONE` marker to advance to the next one.\n\n"
+        "Handy keys: F1 hint - F3 exercise list - F4 topics - "
+        "F5 local docs - Ctrl+Q quit.\n\n"
+        "Press Enter to start."
+    )
+
+
+class WelcomeScreen(ModalScreen[None]):
+    """First-launch onboarding overlay explaining the core loop."""
+
+    BINDINGS = [
+        Binding("enter", "start", "Start", priority=True),
+        Binding("escape", "start", "Start"),
+    ]
+
+    def compose(self) -> ComposeResult:
+        yield Vertical(
+            Static("[bold]Welcome to pythonlings[/bold]", id="welcome-title"),
+            Static(welcome_text(), id="welcome-body"),
+            Static("Enter  Start", id="welcome-footer"),
+            id="welcome-window",
+        )
+
+    def action_start(self) -> None:
+        self.app.state.seen_intro = True
+        save_state(self.app.root, self.app.state)
+        self.dismiss()
diff --git a/pythonlings/widgets/progress.py b/pythonlings/widgets/progress.py
index 0e6bac5..2bdff91 100644
--- a/pythonlings/widgets/progress.py
+++ b/pythonlings/widgets/progress.py
@@ -3,13 +3,37 @@
 
 from textual.widgets import Static
 
+_BAR_WIDTH = 20
+
+
+def _bar(completed: int, total: int) -> tuple[str, float]:
+    pct = (completed / total * 100) if total else 0
+    filled = int(_BAR_WIDTH * pct / 100)
+    return "█" * filled + "░" * (_BAR_WIDTH - filled), pct
+
+
+def format_progress(
+    completed: int, total: int, overall_completed: int, overall_total: int
+) -> str:
+    """Render a one-line display of topic progress and overall progress."""
+    topic_bar, topic_pct = _bar(completed, total)
+    overall_bar, overall_pct = _bar(overall_completed, overall_total)
+    return (
+        f"Topic: {topic_bar} {completed}/{total} ({topic_pct:.0f}%)"
+        f"   Overall: {overall_bar} {overall_completed}/{overall_total} ({overall_pct:.0f}%)"
+    )
+
 
 class ProgressBar(Static):
     DEFAULT_CSS = ""
 
-    def update_progress(self, completed: int, total: int) -> None:
-        pct = (completed / total * 100) if total else 0
-        bar_width = 20
-        filled = int(bar_width * pct / 100)
-        bar = "█" * filled + "░" * (bar_width - filled)
-        self.update(f"Progress: {bar}  {completed}/{total}  ({pct:.0f}%)")
+    def update_progress(
+        self,
+        completed: int,
+        total: int,
+        overall_completed: int,
+        overall_total: int,
+    ) -> None:
+        self.update(
+            format_progress(completed, total, overall_completed, overall_total)
+        )
diff --git a/tests/tui/test_app_pilot.py b/tests/tui/test_app_pilot.py
index 3452193..fdeec06 100644
--- a/tests/tui/test_app_pilot.py
+++ b/tests/tui/test_app_pilot.py
@@ -20,6 +20,9 @@
 def _work_copy(tmp_path: Path) -> Path:
     work = tmp_path / "work"
     shutil.copytree(MULTI, work, ignore=shutil.ignore_patterns(".pythonlings"))
+    # These tests exercise the returning-user flow, so start past the
+    # first-launch welcome overlay (covered in test_welcome_pilot.py).
+    save_state(work, State(seen_intro=True))
     return work
 
 
@@ -69,7 +72,10 @@ async def test_enter_on_picker_opens_selected_topic(tmp_path: Path) -> None:
 
 @pytest.mark.asyncio
 async def test_picker_shows_first_run_start_banner(tmp_path: Path) -> None:
-    app = PythonlingsApp(root=_work_copy(tmp_path), force_picker=True)
+    # Needs genuine first-run state (no seen_intro seed) for the banner.
+    work = tmp_path / "work"
+    shutil.copytree(MULTI, work, ignore=shutil.ignore_patterns(".pythonlings"))
+    app = PythonlingsApp(root=work, force_picker=True)
     async with app.run_test() as pilot:
         await _settle(pilot)
         banner = str(app.screen.query_one("#topic-banner").content)
diff --git a/tests/tui/test_welcome_pilot.py b/tests/tui/test_welcome_pilot.py
new file mode 100644
index 0000000..c98d5bb
--- /dev/null
+++ b/tests/tui/test_welcome_pilot.py
@@ -0,0 +1,62 @@
+import shutil
+from pathlib import Path
+
+import pytest
+from textual.worker import WorkerCancelled
+
+from pythonlings.app import PythonlingsApp
+from pythonlings.core.state import State, load as load_state, save as save_state
+from pythonlings.screens.track import TrackScreen
+from pythonlings.screens.welcome import WelcomeScreen
+
+MULTI = Path(__file__).parent.parent / "fixtures" / "multi_topic"
+
+
+def _work_copy(tmp_path: Path) -> Path:
+    work = tmp_path / "work"
+    shutil.copytree(MULTI, work, ignore=shutil.ignore_patterns(".pythonlings"))
+    return work
+
+
+async def _settle(pilot) -> None:
+    for _ in range(6):
+        try:
+            await pilot.app.workers.wait_for_complete()
+        except WorkerCancelled:
+            pass
+        await pilot.pause()
+
+
+@pytest.mark.asyncio
+async def test_welcome_shown_on_first_launch(tmp_path: Path) -> None:
+    app = PythonlingsApp(root=_work_copy(tmp_path))
+    async with app.run_test() as pilot:
+        await _settle(pilot)
+        assert isinstance(app.screen, WelcomeScreen)
+
+
+@pytest.mark.asyncio
+async def test_welcome_not_shown_after_intro_seen(tmp_path: Path) -> None:
+    work = _work_copy(tmp_path)
+    save_state(work, State(seen_intro=True))
+
+    app = PythonlingsApp(root=work)
+    async with app.run_test() as pilot:
+        await _settle(pilot)
+        assert not isinstance(app.screen, WelcomeScreen)
+        assert isinstance(app.screen, TrackScreen)
+
+
+@pytest.mark.asyncio
+async def test_dismissing_welcome_persists_seen_intro(tmp_path: Path) -> None:
+    work = _work_copy(tmp_path)
+
+    app = PythonlingsApp(root=work)
+    async with app.run_test() as pilot:
+        await _settle(pilot)
+        assert isinstance(app.screen, WelcomeScreen)
+        await pilot.press("enter")
+        await _settle(pilot)
+        assert not isinstance(app.screen, WelcomeScreen)
+
+    assert load_state(work).seen_intro is True
diff --git a/tests/unit/test_celebration.py b/tests/unit/test_celebration.py
new file mode 100644
index 0000000..9a0bcc6
--- /dev/null
+++ b/tests/unit/test_celebration.py
@@ -0,0 +1,10 @@
+from __future__ import annotations
+
+from pythonlings.screens.track import celebration_message
+
+
+def test_celebration_message_includes_count_and_is_celebratory() -> None:
+    msg = celebration_message(292)
+
+    assert "292" in msg
+    assert "🎉" in msg
diff --git a/tests/unit/test_progress.py b/tests/unit/test_progress.py
new file mode 100644
index 0000000..adbbccd
--- /dev/null
+++ b/tests/unit/test_progress.py
@@ -0,0 +1,30 @@
+from __future__ import annotations
+
+from pythonlings.core.state import completed_count
+from pythonlings.widgets.progress import format_progress
+
+
+def test_format_progress_shows_topic_and_overall() -> None:
+    line = format_progress(2, 5, 10, 100)
+
+    assert "2/5" in line
+    assert "40%" in line  # topic 2/5
+    assert "10/100" in line
+    assert "10%" in line  # overall 10/100
+    assert "Overall" in line
+
+
+def test_format_progress_handles_zero_totals() -> None:
+    line = format_progress(0, 0, 0, 0)
+
+    assert "0/0" in line
+    assert "0%" in line
+
+
+def test_completed_count_ignores_names_not_in_curriculum() -> None:
+    # Stale state (renamed/removed exercises) must not inflate the count.
+    assert completed_count(["a", "b", "c"], {"a", "b", "ghost"}) == 2
+
+
+def test_completed_count_empty() -> None:
+    assert completed_count([], set()) == 0
diff --git a/tests/unit/test_welcome.py b/tests/unit/test_welcome.py
new file mode 100644
index 0000000..2786488
--- /dev/null
+++ b/tests/unit/test_welcome.py
@@ -0,0 +1,11 @@
+from __future__ import annotations
+
+from pythonlings.screens.welcome import welcome_text
+
+
+def test_welcome_text_explains_the_loop() -> None:
+    text = welcome_text()
+
+    assert "I AM NOT DONE" in text
+    assert "save" in text.lower()
+    assert "F1" in text