The inevitability of losing at higher levels needs toned down, slightly. Maybe you could make it so that the armor shrines continue to refill your health if you use them at higher levels, even though you can't actually upgrade your health any further? Or fully replace the armor and weapon shrines with other shrines?
My only problem with the entire game was it 'pausing' when I click offscreen... while it's in the upgrade menu. When I 'click' to return to game, half the time... I upgrade my rocket launcher's damage or speed. Made leveling the things I cared about take a -lot- longer :3
@TheFrozenTurtle: The issue is that only the highest number of something is taken. Having -30 pave cost on one character and -20 on another, will result in -30 pave cost, not -50. The same is certainly true for that. Lives may be in the same boat.
Worth a 4/5 for gameplay, but the lag caused by the shadow/light effects (especially in relation to the fast-zombies) made me worry about the game's infrastructure, as well as the bullets always veering off a bit, combined with 0 sense of danger. At the end of the game, I felt bad for having put points into stamina, as I was only hit twice, and both times by the spitters. You get a 3/5 from me. :)
A few minor suggestions: Shotguns should have a wider cone (they're basically pulsing SMGs). There should be a plasma shotgun that basically expands on that weapon type over near constant lasers.
Shoulder weapons either shouldn't reload 'manually' (waiting 30s to get a shot back because I'm in a lull and forget I shouldn't be reloading is painful) or they should reload one shot per button push.
I found a bug... where eventually I wound up with a planet that was growing on its own, in leaps and bounds that shouldn't have been possible (literally, doubling in size, over and over, until it literally touched the sun from the outer ring of my solar system.) I'd even managed to build a stable orbit for it :(
martim: money towers generate their damage in money at the end of every round, so a fully upgraded one nets you somewhere in the neighborhood of 2k per round. They're pretty much a MUST for higher levels (70+)
Oldguard: Just move on, the very next area is full of them :)
Zappy: I went with offhand energy shotty after immediate disappointment in the second energy rifle. Shotgun has a way of hitting with 2/3 bullets on what I'm targeting with the energy rifle.