Wow.. I'm amazed at how much you achieved as a solo dev! Great polished look and feel. Bugs, sure, but they were understandable for a jam and easily fixable. I think all the different game styles were great to mix things up, but they maybe could do with having more reason behind them. My biggest gripes were the platforms seemed overly tricky for some reason, and I couldn't get why I'd only super spring jump at certain times, maybe a hitbox issue?
I think you were very bold to do a hardware upgrade in the middle of a jam, but this whole game exudes boldness, so I'll guess it's your modus operandi! Post-mortem is a great idea, I'll try to do my own. I always do a retro of them anyway, otherwise you can't improve. Hope you score well!