This is a really, really good game, but I agree with whoever said it first: It's kind of a bummer that the upgrades only ever amount to picking the strongest thing you have and letting it fly, it'd be neat if there was more to it. Also, it's straight-up dumb that you unlock the final upgrade by getting to the point where you no longer need to play the game.
This is what people in the 80's thought video games would look like in the future. Pretty good, though the controls feel way too loose for something like this. 3/5