The concept art of this is awesome, and the soundtrack rules. Sounds like something almost more like what I think a lot of people would've wanted Metroid 2's soundtrack to be, as opposed to the more purely atmospheric soundtrack that game ended up with. A nice mix of melodies and atmosphere make this soundtrack one that would likely be quite fondly remembered in a gameboy game, so it really has down the "feeling like a gameboy" thing down well too, as well as the core theme of the jam.
The soundtrack also reminds me a lot of Gargoyle's Quest, honestly, which to be clear is a very, very good thing.
Also, I love me a good Mega Man inspired game, so the idea that this all would be playing for a game inspired by that series? Yeah, you can bet I'm on board with the idea.
I do have some thoughts on the proposed gameplay ideas that I'd like to get into, since everyone else is already going into how good the soundtrack is, and I've already gotten into the soundtrack about as much as I reasonably feel I can. Also, I feel the gameplay ideas are worth talking about since they seem interesting, though I think it's hard to gauge how well it'd play in practice.
I think the idea of having a long list of spells with highly varied abilities on a shared magic meter in a run and gun is interesting, but I do wonder if it'd potentially make the game feel overly clunky in practice if not executed well. You have to either press select to open a menu to change them, or the alternative is that select might cycle through. Either way, it's something the game would have to account for carefully, which in fairness, the Mega Man games had to account for their boss weapons carefully, so, nothing new there I suppose, even if these abilities sound pretty different from those in practice.
That being said, it's one of those things that you can't easily gauge without actually playtesting and fine tuning it, and were it made an actual game, no doubt that such playtesting would be done to fine tune it until it actually does play well. Since like... it's a concept that can play well, to be clear! This is more something to keep in mind should you ever pursue finding a way to make this game concept a reality. One of those "this is good, but look out to make sure this doesn't happen since it could if you aren't careful" kinds of things, if that makes sense?
I think it's an idea worth giving a go, as somebody who thinks it's worth doing things in game design even if there might be obstacles to pulling them off well. It's just worth trying to identify and remember which parts of a given game concept are the parts that might require a closer, more careful look to pull off well while designing a game.
Oh yeah, also? I actually really like the idea of fitting a parry into a game like that. That sounds like it could be really fun if implemented right, especially since it'd probably help balance out some of the issues with managing a long spell list by giving you a difficult but consistent, reliable way to deal with some things even when you're still figuring out what spell you want to use for a given situation.
Overall, I'd be very intrigued by a game with those gameplay concepts if it were ever made real.
Definitely would be a concept with potential, which, when combined with visuals like that and a soundtrack like this? Yeah, I think a game like that would probably be very, very fun to play, suffice to say.
Oh yeah, if you ever get a chance to make a game... since I'm here, I do wanna give a tip: Make sure to get playtesters when you can! On a tight time constraint like a gamejam, it isn't always remotely feasible, but I'm speaking more-so a hypothetical full scale non-jam game or such.