Right, I upgraded everything and got all achievements. So I stuck with it.
The thing is it's nice, and there is something satisfying about the destruction you cause and as always with upgradable you want to see how much better the next unlock makes it.
The graphics are really nice and the tune for it is cool. This is the short part.
Now I am going to list what I think is lacking and how it can be improved.
1) There is no real challenge to it. No challenge equals no gameplay. This game is basically holding down a mousebutton while constantly moving in one direction. Bullet avoiding is minimal and it just gets boring real fast once you realise this. You still get 3 points though because it was short enough to keep interest.
2) I counted four different enemies. That is ok I guess for a short game, but a bit more variety would have kept my interest for longer
3) It would have ben nice with a boss battle like someone else mentioned to sort of have a proper ending.
4) There is no ending as far as I could tell, I got my combo up to 1600 almost and the timer ran out.
WOuld have been nice with a proper ending. Perhaps have levels in it.
5) Sound assets. Having hordes of people saying the same phrase was annoying as hell. A bit more variation would have been nice.
6) Controls - Rather than just being able to go left or right at different speeds, up and down would have been nice with a bit more challenging rate of fire from the enemies. AS mentioned before, you can basically hold down the button and just pick one direction as is. You'll probably get hit by some bullets but chances are you'll make it fine til the timer runs out. ---> Not really gameplay.
The graphics and atmosphere are great and I would love to see a more fleshed out proper game that builds on this. Perhaps you can completely change the gameplay and have missions in a sequel - like beaming up certain targets (cows!) and such. Have stealth aspects and so on.
I would definitely like to see more.