KeeperFX, like the original game, has several hard-coded key combinations. Alt+X to close the game, Alt+R to change the resolution, and several more.
Unlike the original game, KeeperFX allows you to use Alt in the define keys menu, and in doing so, allows you to define key combinations already in use. This leads to conflicts if a user unknowingly selects such a combo.

Since being able to use Alt for zoom keys is nice, I think it would be best for KeeperFX to have a clear list where all system keys are defined, and the define keys menu excluded these combinations.