single letter makes FAST (your character) or SLOW (enemy).
I got to end on Kids level
Game is simple, but fun. My wife wanted to play it again tonight. I can't say that for many video games.
Idea is to shoot bad guys and not get hit or run into boxes/floppy disc/etc, else you lose a heart - lose 6 hearts and game is over. You can get hearts and power ups along the way.
In single player mode after awhile you go to new level with different video game themes. After 4 or 5 levels you win game.
Demo really represents the game, so use that to judge if you should buy it.