You can't deny that this game is kinda fun.
Gameplay is cool that it fits in the genre of "arcade". You move back and forth, and you shoot in a 180 degree radius. Just watch out for bullets, kamakaze planes, and even atomic bombs from planes that seem to have an unlimited supply of them. Honestly, if you do not blow up the bombs it drops, it blows up everything on the ground... well probably just you. But, if you blow up the plane dropping them, all you get is the normal explosion. This game does not win for realism, but it sure does win with just some plain fun. Even the bosses are pretty challenging.
Variety kinda plays a good role in this game. It comes with the basic story or campaign mode, the survival mode, the boss mode, and the multiplayer/online mode. Graphics are pretty "online PC"ish. It's very flashy and things are pretty simply detailed. Nothing beyond simple. The backgrounds are cool to look at, but it's still the same gameplay in the foreground. So, that doesn't change. What is a little irritating is that sometimes the screen gets way too crowded with planes, ammo, smoke, explosions, lasers, etc. It's too much to look at. But, I guess that's the challenge.
Sound and music is a little muffled, but it's decent. I don't like the sound that much to this game. I don't think the sound effects were chosen wisely for this game. And the music is pretty... well terrible. It's repetitive, too. But just mute it, and you're okay.
Controls are very responsive, but using an analog stick to move the cannon back and forth in 180 degrees really becomes a pain. I think there is embedding on my thumb right now.
Finally, playing online is actually pretty fun. I've played a couple games, I think it makes it more fun since you have teammates in this game. You can't argue with that.
Overall, Heavy Weapon is pretty good. It's not good, but it's okay. There is a few flaws to this game that prevents it from being absolutely replayable, but once you finish, you probably won't touch it ever again.