Really satisfying! Love the kind of combos you can do. At first I didn't notice that my candy took damage by my punches, maybe you could make so the candy flashes red when taking damage or something?
Also right now there is currently no reason to save your upgrade points. What if you removed level 5 from each upgrade but made level 4 as strong as level 5 but make it cost two points? That way if you want the best you'll have to do one round without the extra upgrade.