I want to write in defense of the randomness ... it's really a key part of the game. Taking that away means the biggest monster always wins, and hence takes away the strategy. Right now there's plenty of strategy ... I just won 5 times in a row with a well-tuned 1550 deck against the computer's 2500 deck (I lose sometimes, but win more often than I lose). Making this a "biggest card wins" game would mean that a 1550 deck would have no chance.
Possible to beat using the basic monkey + 10K in the bank, so some rebalancing would help. The style is very nice, though, so it's certainly fun. I'd suggest that, when placing towers, you snap to the closest viable location.
If you have two freeze towers next to each other, it can take an awfully long time for red balloons to go through. Maybe turn off freeze towers once all the unfrozen balloons have been popped?
 "Monster Master"){kind=icon}
 "Bloons Tower Defense"){kind=icon}