Jumping feels like it has a delay (even though it doesn't). To fix this, you should bind jump to space press, not space release.
You might also rethink the map design and door placement. Right now you can go everywhere with using nothing more than one blue key.
When you're moving and then jump while continuing to move, the walking animation stops and the character slides on the floor.
There are passages you can walk on while not being able to see your character. When you zoom in all the way, you can look through the wall in front of the character but it still doesn't feel good.