Okay, I at this point have played a fair bit of the game (some bugs made progress difficult so I admittedly gave up after the, admittedly rather fun, grappling hook started phasing me through walls so much that I could no longer progress as intended easily anymore) and I think I have more I want to say.
Having seen what the game has to offer, I actually really like a lot about its concepts, but I feel the execution needs a lot of work. I actually highly recommend other people give it a go and give feedback on what changes could potentially help though: There's a looooot of potential for this to become something really cool if it ever gets fixed up more, and as-is I think there's some neat ideas here worth a look.
So, let me start with this: At first, I honestly didn't think the power management mechanic was doing the game many favors. I feel like until you have more abilities, it mostly just makes the game feel clunky.
At this point though, I understand that that's actually possibly on purpose, given how the game picks up once you start getting more abilities. Even if it's an accident, I'm a lot more cool with the mechanic now that I've seen where it goes later.
That being said, I might suggest making the melee combat, short lived as it is, slightly easier to avoid taking damage during, even if it's not a focus of the game.
Alternatively and/or additionally, it might be worth making checkpoints visible so the player can know where they'll be respawning when they die, making it less of a worry of "oh no how far back am I going to have to go if I die to this early enemy?" Unless that worry is on purpose, of course, in which case I might suggest at least placing flying enemies in places where they're less likely to get in the way of attempts at platforming before you have a proper weapon...?
Oh, also, I recommend putting a sound for when you properly land a melee hit, and particle effects for when you land a hit in general. It's a bit hard to tell when a melee hit lands as-is, and it'd make the ranged combat more satisfying.
Just some possible thoughts for tweaks to make to make the early game potentially leave a stronger first impression than it currently does.
Once you have a double jump and a gun though, the game starts feeling pretty fun actually? The game feel isn't the best, the gun could do with some reload sound effects and/or a shooting sound possibly, things like that, but I think the idea of managing power is a lot cooler once the game starts using it as part of a really neat reloading mechanic instead of just for the early game movement and melee combat, it actually adds some unexpected depth to combat I expected to remain pretty straightforward.
The double jump is of course mostly a pretty basic double jump, but it also actually makes power management on the movement feel more important instead of just feeling like you have to have power at about 80-100% at all times on both legs, so it works really well here.
Unfortunately, this is where I get to the part where I have to talk about the grapple arm thing. It's a really fun ability on paper actually, but unfortunately the programming on it is really buggy and it can latch onto walls behind other walls, allowing you to sort of phase through them. And sometimes, this happens entirely on accident on the player's end due to it being a bit tricky to aim it at the exact wall you want to sometimes.
It's an ability with a lot of potential, but it did make climbing up to an area I needed to access a bit overly difficult, so while I have a feeling there's more neat abilities awaiting me beyond that point, I think I've seen enough to generally get the idea on the game to where I think this is where I'm going to call it for now.
In summary, the core of my thought on this game is that it actually has a lot of really neat ideas, but broadly the implementation of most of it is too buggy. Though in fairness, it's a gamejam game, so it's not like bugs are exactly unexpected for the territory. Especially for a first time gamejam game maker.
That all being said, I look forwards to seeing either a more fixed up version of this and/or further games from this developer in the future! I think the creativity is there, it just needs more time and polish, and I feel like the developer can absolutely pull it off given more time. If it ever gets updated more, I'll be sure to say my thoughts on the changes and any parts of the game I didn't really get around to here or in my previous comment.