perhaps consider offering to buy an entire new store... like a franchise.

Randomized genetics between games. Once you figure out that breeding FinA with FinB yields FinC and likewise for body types it gets a little boring. It would be cool if the yields were different for each game. That way every game would be unique and would increase replayability.

I agree with all. MOre tanks and also more levels of research etc. Onece all is purchased ...it gets very mundane.
No music in fish store...just the sound of the cash register.:)