Regardless of which wave you're currently trying to complete, you'll see the same background, albeit with a different color scheme. Toy Raid is a simple, unassuming game that doesn't put too much stock in its visuals. There's not much to see, other than the flying (and exploding) planes and paratroopers.
Toy Raid only contains a smattering of sound effects, but they are all used liberally. The computer voice should be familiar to just about anyone who has ever played a game. The squishy sound of exploding paratroopers is the real stand-out, even though it's repetitive and extremely cartoony. There's no music, but in this kind of game, music is not necessary (or even practical, for that matter).