So having gotten tired of playing the same handful of tracks in Rock Band Unplugged I decided to give DJ Max Fever a try. The game is pretty much what you would expect from a "falling bricks" rhythm game with a few notable differences from something like Rock Band or Guitar Hero:
1) You are actually playing the notes/sounds
2) The game is very forgiving when you don't hit notes exactly
3) The game can be freakishly hard with up to an 8 button mode (also has 4, 5, and 6 button modes) and multiple speed settings
For 1) when you press a button you hear a note/sound at that time even if the note hasn't gotten close to the bar at the bottom yet. In GH and RB you would hear a "missed note" sound instead. In DJ Max it feels more like you are playing the music, since, well you are.
With 2) it only counts as missed note (a "break" in DJ Max parlance) if the note falls off the bottom. If you hit it too soon or too late (but before it drops off the bottom) you just don't get as many points for that note.