Right now the way you can affect your bit is using battlechips or by increasing the level for HP and damage. My proposal is to add another system where each level adds slots fors equiping armor parts. Armor parts could drop at the end of a dungeon and provide different benefits such as:
Increase flinch duration
Remove flinch
Increase HP
Add speed
Add power to chips of specific element
Increase chance for items
Increase money on beating enemies
This would add another layer of depth