There are some problems....
The game, for what it's worth, seems to be okay for the most part. It wasn't too short and the weapons seemed to be pretty decent. Overall it was an okay challenge. However there are problems with it...
1.) Lack of an ammo bar for the basic weapon - I noticed that after shooting so many bullets, it stopped firing for about 2-3 seconds before I could shoot again. Seeing how there was no ammo/power indicator, I felt this should NOT happen. If it has limited ammo/power for every so many rounds, GIVE AN INDICATOR!
2.) The shop button seems to be unresponsive - Just like with Eon264, the shop button would not respond at times when I clicked it. I believe the most I had to click it was 3 times. If someone has to do that to bring up the shop, there's a problem. And on a side note, take the button out completely and make a shortcut key to the shop; it'll be MUCH easier.
3.) Exiting the menu after repair causes damage - Whenever I got low on health I'd go and repair to full. Yet when I leave the menu, I took damage. It was anywhere from 1-3 hits, so I never had full health. And most of the time, this was after all enemies were cleared out and there were NO BULLETS ANYWHERE.
4.) Hit boxes for enemies are too tedious - When shooting right at an enemy, I noticed they were not taking damage. I had the aiming cursor over the tank, I was clearly shooting accurately, yet no damage was being taken. That is a SERIOUS problem. I shouldn't have to aim at some spot that's 3x3 millimeters just to damage a HUGE enemy. This isn't a freaking Touhou/manic shooter game!
5.) Something wrong with the end boss - Half of the mines it would lay wouldn't go off when I rolled over them. The boss suffered from the lack of being able to damage it (see problem 4) and also the damage area for the beam it fired was TWICE THE WIDTH of the actual beam graphic! And also inflicting a "SURPRISE CONFUSION" status on the player when hit isn't so great either. It forces the player to take WAY more hits than they should be. It would be nice if there was a warning about it, but no, no such thing exists in the game.
6.) Low variation of enemies - In your Author Comments, you seem to imply that through the game we will constantly see different and "evolving" enemies. This is (sadly) not true. By about half way through the game we've seen every single enemy there will ever be (not factoring in bosses). After that point, all you do is start throwing what are essentially Zerg Rushes at the player. You could at least reskin earlier enemies, boost their life, power, and speed a bit and toss them in.
Now far be it for me to be so picky, but those were the glaring problems. MANY of them being actual problems. One of them, more or less, is simply pointing out a lack of something you said would be in there.