Playing Pool Of Radiance got me learning the ins and outs of 2nd edition AD&D and I came to the realization today that I prefer games with a magic points or mana system. Probably because I grew up with JRPGs which exclusively deal with MP over spell slots. Don't get me wrong, D&D is great, but it's such a pain when you get into battle and you realize you forgot to memorize Detect Magic and now you have a bunch of potential good loot.
I'm actually kinda liking this dumb idea, imagine if every level you could increase the X or Y dimension of your inventory, so if you wanted to eventually cast some W I D E spells you'd have to focus on columns and give up the ability to cast TALL spells that need lots of rows to fit. Or you could forgo both and just go for the maximum-area square full of generic moderately-shaped spells.
Metamagic works by literally placing spells next to each other, maybe certain elements react poorly to being placed next to each other, a version of "silence" that works by shrinking the target's spell grid and disabling anything that's sticking out over the edges.
Sounds like you should play Backpack Hero.
I realized halfway through describing this that I was just describing Jump Super Stars lmao