Game froze when I actually beat it by killing the guy, sad that there isn't a victory screen. Interesting that I had to save up to 700 beforehand and get 4 necromancers down before things scale, eventually getting 400 necromancers becoming completely balanced.
Found a bug, if you start the defend the portal event, and then activate an obelisk again by walking into it, the red screen goes away and no more monsters spawn in, not sure what time the game ends because haven't beaten it(did reach 7 minutes), but waited a good bit and it didn't end