This game is your average timekiller game.
The gameplay has a good upgrade system, but the gameplay is repetitive and a bit dull and uninnovated. Also, there are some lag issues, especially on the last boss. Graphics and sound are average.
Beating the boss is pretty simple if you have the right setups. The only weapon that really hurts him is the rocket launcher. So get that, the damage upgrades, and the speed upgrades, and you're good to go (freeze aim, and health/armor upgrades help ward off the boss' minions).
Nice gameplay (up to the boss, who was too hard imho). I did have the slow-down with the boss that other people experienced, but flash asked me for more storage space and the next time I played it was ok.
The day night cycle was a neat addition, although the night-vision upgrades eliminate that as an issue later in the game (which is backwards - normally the game should get more, not less, challenging). Ditto with the health upgrades. You can die in one hit on the first level, but after some upgrades you're much more resilient.
So - fun to play, but more thought needs to go into the progression of difficulty and how the upgrades fit into that. Also - allow the player to cycle through the weapons with the keyboard (Q and E, for example).
The fact that you die in one hit from any of the enemies type is still bugging me. But it does give a good sense of challenge to the game. I love the diversity you put into the game. How random loot appears from the monsters you slay. And the diversity through the levels, giving each level it's own "thing".
It was slightly below average. It was rather uninspired, and unbalanced really. I got every weapon after a few runs on the first level. The difficulty curve from the regular game to the boss is practically a 90 degree angle. If you're going to make an easy game, why would you make such a difficult boss? Overall nothing special, kept my attention for a few minutes.
You could have used the mouse wheel, the numbers, Q and E, but you decided to change the weapons clicking...