Operation: MOUSE is a lot better than Sim: Life and, unlike The Kane Project 2, doesn't take itself too seriously. It's bug-free, and has a few interesting graphical effects. The gameplay isn't too easy or too hard, nor is the game overlong. There are a few laughs in there, too, if you look.
The bad news:
The writing is atrocious, as the humor and characters generally fall flat, despite a frantic attempt by the author to increase the comedy of scenes by increasing the volume level. Repeated fourth- wall breaking jokes are executed poorly, and the ending is an intentional anticlimax, reducing the game to the level of a pointless shaggy dog story. Endless shaggy dog stories may be fun to tell, but the joke is always on the listener.
The gameplay doesn't reveal much of anything new, with the exception of one neatly executed puzzle, and has two thoroughly senseless sequences. In one, you have to touch an object twice for a vital clue, even though you have no reason to touch it once., and another sequence requires tedious guesswork.
Still, this is a decent game. Just try not to flinch at the cutscenes too much.