rn the game feels more or less like a massive grind from one expansion stage to the other. Maybe add a bunch of side things to work towards like also giving the bunny expansions if you buy enough stuff from her. Or maybe dungeons, a string of battles where if you beat them all you get alot of exp. And also some expensive permanent upgrades in the shop, like a stackable exp multiplier.
Also some new abilities on level up would be great my strategy hasn't really evolved since level 5
Edit: I've learn that the bunny does Infact expand. Just only took like... a bunch grinding and me spending a Lotta money.