This thing is something that has yet to come out recently. The only problem with the game I had was that it was frame spiking from time to time but since I didn't see any more responses about it it's probably my computer or internet or browser or something so it can't really be taken to damage this game in any way.
The game was simple, epic and challenging. (If you're like me and test out how far you can go before breaking down.) Altough it is simple and at normal the AI seems braindead (Probably the only reason why people think is easy) and I didn't expect much from the higher difficulties and didn't really feel like going through a round at a different difficulty.
That's where the great feature of the scaling difficulty comes in. At start I killed everything. Later too but near the end I actually had trouble with it due to the AI actually snagging any weapon on the field (I played with 10 AI) leaving me with the very limited stock weapon to actually think about what I'll do and not just rush in and get shot down.
As for the "ideas" by people writing reviews here. I strongly suggest that you don't add multiplayer or upgrades.
As far as multiplayer goes, the community usually spoils the game. And having a game as epic as this spoiled by some stupid community is something I don't want to see. EVER.
Along the lines of upgrades. The game doesn't need it and I honestly wish people would stop being so cheap to need to be WAY stronger than the enemy to be satisfied. Here everyone's even and if you set your difficulty right you'll most likely have problems getting to the top of the leaderboards at the end of the game. A sense of feeling stronger is actually being in the top ranks on a harder difficulty. Games with equal terms boil down to skill and people should develop them.
Being you I'd just try to optimize it a bit so the framerate spikes wouldn't happen (Currently running on Opera Win 7 64 bit if that does anything.) but generally this game has no downsides.
It's an epic behemoth of a diamond rank game.
Final verdict: VERY strong 5/5 stars.
*RAGING SEAL OF RECOMMENDATION*
-Numeris1672