What is it: Indie first person espionage game. You can download it free from the developer: 
keys are remappable, but you need four keys for movement and three keys for items/jumping.
You can map two different keys to the same function. You cannot map two functions to the same key, though.
Mouse is required.
One handed play seems like it would be very difficult.
You can play with a gamepad, but I haven’t tried it.
Colorblind should be fine, there isn’t really a need to discriminate different colors. No ability to change contrast though.
You can adjust sound effects volume and music volume independently.
You can save at any point in the game.
There is only one point in the game that requires precision, but constantly saving can help alleviate this.
fullscreen or windowed.