Untested
The concept is great, as are most of the levels. But I can't give a high score to a game that requires 100% luck to get more than halfway through. But more on that later.
It starts off on a bad, bad, very very bad note: level 1-1. It's nearly impossible. You have JUST enough bullets to clear it, and that's only if you aim perfectly and get very lucky with bounces. It takes an eternity, and it's really not that fun lining up shots and then waiting for them to fall off the screen over and over.
Once you get to 1-2, though, the game picks way the hell up. Suddenly the game becomes fun. You get all sorts of cool ammo like scatter, big, weird...square explosion blast. And the designs are neat and challenging.
But then comes level 2-3. It's horrible. It makes level 1-1 look like any level that is neither 1-1 nor 2-3. For one, the concept is flawed: hope your shots bounce the right way. Unless you're a Terminator or enjoy doing hours of math in your spare time, there's no way you'll know if you're going to win unless you've already done it. You just have to shoot into a column and hope for the best.
But that's not the worst part, not by a long shot. The worst part is when your shots just phase through the metal blocks, completely wasting them. And it doesn't just happen sometimes, it happens ALL THE TIME. The hit detection is horrendous. Get to 2-3 and shoot a few reverse gravity shots into an empty column and you'll invariably see what I mean.
Thus, I cannot complete the game without hoping to god none of my shots bug out, which at least one always does. And I just don't have the patience to redo a level over and over just because it was coded poorly.