as a game, it's okay
Before I actually review, let me just say that I'm not gonna jump on the bandwagon and call you a monster, or insinuate that you should be locked up for making a flash game.
The game is passable at best. The graphics are mediocre by todays standards, but it's a nice little bit of nostalgia for the 8-bit era. The music is actually pretty good. The violence is, as expected, over the top. It's not funny at all, but then again, I have a feeling that it wasn't meant to be.
The one thing I'll say as to what the game is based on is this: the choice to make a game on an actual, real-life massacre like this was a poor choice. I doubt you meant to offend anyone by making this, although you must have known the controversy it would cause. Games with ungodly amounts of violence like "Grand Theft Auto" and "Gears of War" are fun because they are fictional. I really believe that this game was made with poor taste.
While I may defend your freedom of speech, I do wish you would've chosen something else to make your game out of.