I tried playing through the game three times. Here are some observations:
I liked the character design. It was clean, simple, and nice. The movement was okay. I think the walk/run could be a bit faster. The jump mechanic was decent, a little floaty. Rolling felt good. I especially liked that you could initiate the roll mid jump.
I feel like the shooting mechanic could be improved in one of two ways. Either make the animation/shoot timer a little faster or have it so that the longer you hold down the button to shoot the more velocity the arrow has (with some max velocity).
Adding even some small sound effects would improve the feel of this game greatly. You still have ~9 hours left. Just find some simple sounds for jumping, shooting, enemy dying, etc. Some simple background music would improve it a lot too.
Now for the parts I did not like/bugs:
There are a few spots where you move downward and there isn't much to indicate that there is going to be ground for you to walk on. I think just raising the ground up a little more in those areas or giving a little more visual indication that you're not going to fall into a pit would make it feel a lot better. Speaking of falling into pits, I fell into one and kept falling for eternity. Try to implement some sort of simple restart mechanic before the jam ends. In the spot where you have to jump onto the individual blocks in the air, when I hit the side of it I stuck on to it instead of falling.
I wasn't a fan of the boss battle at all. The way the boss attacks was kind of annoying. I liked that his color changed as he took more damage, but I kept shooting and shooting and it never died. I also fell into the floor in the boss fight in two out of the three times I played the game. I also saw this error in the debugger: "ERROR: Object::emit_signal: Error calling method from signal 'animation_finished': 'RigidBody2D(boss_segundo_teste.gd)::_on_AnimationPlayer_animation_finished': Method not found."
Overall, I think it was pretty good for a first game jam. I think if you keep working at this prototype you could make a fun to play game out of it!