Now, this would probably take a good amount of effort (and it might be impossible since I don't make games), but what if there was a card that turned a prey card into a pred card (which would be added to your deck), with corresponding effects (Mufi and Sachiho being snowballers like the Mobi variants, princess not able to be removed, etc)
Another thing I think would be nice is if there wasn't caps (for digestive power and capacity) in infinite mode like when you get that one power up in campaign, or maybe instead a system (in infinite) where earning points would allow you to buy power ups.