*phew*! OK I just finished my final marathon session with this one. For some reason I really liked this game, but I'm glad it's done with. It's all too easy to waste time with!
By the end I had 500 ammo, 201 gunmen, 25 crafstman, 100 silo workers, 1000 base hit points, all upgrades (sniper, etc.) and had reached level 58. My monthly salary was $200,150. That's when about 30 tanks on screen at once clogged up the screen so much that I couldn't get 'em all. My only regret is I might have survived if I'd had more craftsman. I was saving up to get 25 more for a total of 50. But there were diminishing returns so this may not have helped either. 100 silo workers were barely better than 50, and 50 not all that much better than 25.
The worst thing was the rockets were barely effective against the tanks, who come in swarms in later levels. Things started to get slow, too, so it was hard to know what had been destroyed and what still need a-killin'. This was on an Athlon 64 X2 4200+ and with Flash set to Low quality.
I'm thinking the designer didn't really think about how the later levels would work, they probably just setup a linear increase in the number of enemies and left it at that. I did notice the increase in enemies started to taper off around level 30 though.
I know I'm going on endlessly about this and nobody probably cares, but I had to tell someone, lol. This really is one of the more fun web games I've played in a long time. Simple and mindless enough to just pick up and play for a while, but also with an interesting strategy element. If a sequel were made I'd really like to see more upgrades and more powerful weapons. In the later levels you really need something like an ion cannon or nuclear blast.