@my previous comment (16 Oct.): the 'bug' is that the stat pickups appear before all monsters are defeated, not that you can gain infinite stats from it.
Possible bug: The mobs that appear after defeating a ghost apparently count towards the number of monsters needed to clear the room, so the +5 attack/crit/health orbs appear before all the monsters in that room have been defeated. Example: there are 2 ghosts left, beat one and 1 of his spawns and the +5's appear while there's still another ghost.
Tower names and cost pointed out somewhere would help ;)
I'd had to build a tower to see what it's special was.
For other players, the towers are: regular-slowing-fast shoot-poisoning-sniper.
Nice game, but it's got at least one bug: neverending level without enemies. I haven't finished the game yet since I got the bug twice in 2 times playing, on different levels. Seems to happen after upgrading...
So you can infinitely farm stats, and become super strong?