This is a really well executed game. The artwork is fitting. The background track is really good to listen to. The best part of the game is the core mechanics. The creature evolution system is very good and refreshing. You’ve managed to pack a lot into an “upgrade system”: regular stats upgrades that are permanent (+1 strength, etc.), temporary powerups (+10 currency, increase stats for current creatures), and behaviours that can be changed dynamically (hunt, collect coins, patrol, etc.). This makes sense for a dynamic environment, where you can change things a bit in response to the current situation. The game did start lagging, especially real bad when I had chosen “collect in the center” behaviour for the swordfish. Didn’t encounter any bugs. As mentioned in other comments as well, I wasn’t sure what some of the upgrades mean.
Took me a few attempts to figure out how to play this. In one of the runs I managed to stick around and beat back the challenging parts where the pollution targets a particular creature and you have to switch. Am at wave 149 now. Although I made a mistake early on and the small fish started costing 6 and couldn’t afford it after that. Managed with the other two though. Until about 60-70 it was about being sure that you can beat off the pollution waves. Then I wanted to see how far I could go. I think the player is quite powerful now, not sure if the game will “come back”. At least until level 50-60 at least I would say the game is really well balanced. Not sure if I can replicate the run though :) But from the first few plays (when I reached upto wave 15-20) the game surely makes you want to improve your strategy and do better each time.
Overall this is a fun game with some cool mechanics, and a refreshing take on the defence concept. Great job!
Playthrough video from wave 83 to 149: