I almost immediately encountered a bug that caused jump inputs not to be recognized, confusing me a bit at the start. Restarting the game fixed it.
About the gameplay, it feels kinda floaty, the attack animation kinda locks you up, and the range of it is either way too short or inconsistent.
It's also a pretty... unconventional idea to put a very difficult jump right at the start. Not that the difficult jumps later on are any less bullshit, but I get that you couldn't really get a tutorial-type level going for a game jam game. Though later on there is a semi-tutorial section, where you jump on the single-block platforms, but above a safety net, rather than an endless pit.
In general a lot of the jumps seem very difficult, possibly because the player hitbox is larger than visually shown, which isn't intuitively understandable, and possibly because the devs are of course intimately familiar with the function of the game mechanics, and from that point of view what may seem trivial is actually quite rough.
The respawn mechanics feel almost entirely superfluous, mainly because the only thing that seems to get carried over is which enemy is dead. And considering the enemies don't *really* pose a threat, that's not really much of a benefit. Getting immediately pushed back to the start, especially with these rather high difficulty jumps (maybe the floaty controls and seeming lack of coyote time just makes the jumps way harder), is a big punishment, and also the same punishment you get from losing all lives. So without checkpoints, or making fighting the enemies a bigger part of the game, the lives system can easily be left out.
The music and graphics are nice enough, though the music is a bit loud, and I have a few points for the graphics too:
-I don't quite understand what the point of the white outlines is, they might be common but generally more subdued than here
-The attack animation of the player character is kinda bad, it lacks impact, it feels like the knight is slowing down the attacking leg before reaching the target. The range of the attack is also pretty bad, but at least the gameplay range and visual range are pretty close, so that's good.
-The characters don't feel like they belong in the game world, both from a theming perspective and a pure visual one. Maybe it's the white borders, maybe it's that small gap between character sprites and floor, they just seem detached from the world. Theming-wise, I think it's obviously a time limitation, and that's fine.
-A graphical/gameplay issue: If you jump over an enemy with a throwing attack that faces you (like that third enemy, the skeleton pirate), they violently oscillate between looking left and right, and their projectile seemingly switches sides too, making it hard to read, and possibly instantly taking health off you when you land on the other side
In conclusion, for a 48 hour game jam game, it ain't bad. It's obviously lacking a lot of polish, and (more importantly) playtesting by other people, but still, not bad for what it is. I'm sure you'll only improve :)