the game seems that it could be nice and interesting, it's alright for being a start. But i believe there's more that can be added among time to make it really good.
- Music needs some rework as it was mentioned, and will make it more enjoyable
- Collisions with the spikes sometimes are a bit off, and you die without being really close to them.
- Adding more text or explaning the story a bit further will make the player get involved with the objective of the game
- Some objects like the ladders need at least for the first time have some visual tutorial or something to let people know those are ladders and that they can press up to climb. At first there's a high chance people won't realize those are ladders
- Adding controls or a small tutorial in the beginning will also be a good addition.
All of this requires a lot of work of course, but if you plan to expand the game or keep working on it, i hope this advises help you out. Overall the game is fun and i had a good time trying to beat it!