We've been having trouble describing Everyday Shooter to gamers. Maybe you'll have a better way with words than us: how would you describe Everyday Shooter?
Everyday Shooter is like a music album, except instead of it being a collection of songs, it's a collection of shoot-em-ups. Each track/song/level is completely different visually, musically, and in terms of gameplay. You can see the screenshots to get a feel for the diversity in levels.
Each level focuses on a different chain reaction system that is not explicitly explained to the player. So with each playthrough, the player gains a sense of wonderment as they discover the nuances of each enemy and how they relate to form the greater chain reaction system. Although this gives a slight puzzle-y aspect to the game, make no mistake, this is a SHOOT-EM-UP, and not a puzzler.
One popular aspect of Everyday Shooter is the way it treats audio. All the sound effects in the game are guitar riffs harmonizing over an all guitar soundtrack. Bigger reactions causes bigger riffs to play. Thus you'll feel as if you're playing along with the music, except that your intstrument is the shoot-em-up!