BoomsticK -- and no, I'm not going to keep using that capitalization -- is a relatively straightforward shooter with a few interesting ideas balanced out by a few irritating flaws.
The basic concept behind Boomstick is quite simple: you have a shotgun, various brightly-colored shapes flit by overhead, and you have to shoot them. When you do, the shapes drop ammunition which you can pick up. In the early levels, at least, the shapes pose no threat to you, and your main concern is running out of ammunition -- each shot gulps 10 ammo, and if you only hit one target with each shot, you'll quickly run out. Thus, the key to survival is hitting two or more shapes with every shot. This is the first flaw of the game -- it slows down the pace and means that you have to spend time waiting for the perfect shot to come by, which makes for a pretty boring experience. Also, your character moves frustratingly slowly, so even if you do manage to pull off a good shot, you may not be able to collect all of the ammo dropped. But, in any case, giving an advantage to the player with infinite patience is generally poor game design.
As the levels (or, as the game calls them, "tiers", for no explicable reason) go by, eventually more hazardous enemies appear: first, enemies which shoot at you, which cost you ammo, and then finally enemies which aim to directly collide with you. This is the second unpleasant surprise the game has in store -- after you've been cruising along for a large portion of the game without any worries other than your ammo stock, you can all of a sudden be killed. Fortunately, the game doesn't force to restart from the beginning (which would be unbelievably poor design), but even still it's rather a rude shock the first time. (Especially since, once you restart, all of your carefully stockpiled ammunition is gone; fortunately, once you reach these last few levels, targets are generally plentiful enough that ammo is no longer a huge worry.) The boss in the last level is also quite the challenge, especially since you still have to play through the last four levels every time you fail to beat the boss.
The graphics are nothing special; the shapes (as mentioned earlier) are brightly-colored, though. The background music is not bad, and fits in well with the slightly futuristic feel of the game. The sounds are nothing special, but they don't take anything away from the table, though the sound when you get squished is surprisingly graphic. The spelling also gets shaky when you get to the really-high-multiple kills, unfortunately.
Overall, the ammo-conservation mechanic is a neat feature in the game, and definitely is a nice feature to have in a shooter like this, but the frustratingly slow pace in the early levels means that this is not the best realization of that idea. The badge is a worthwhile challenge, though.