I only made it to level two before quitting.
I don't know if you were deliberately going for a retro difficult vibe to the gameplay, but it just wasn't my cup of tea.
If you weren't:
Maybe you've come to the same conclusion but, obfuscating the progression so early on was bad design IMO. Hiding a vital powerup behind a secret wall was questionable (I guess the fact that you put platforms down there was a bit of a tell) but given the pits instantly kill you and send you to the start of the level, I wasn't incentivised to experiment.
Even in a hard game, I think it's better to be guiding early on, and save the hidden stuff for bonus extras/collectables etc. (Maybe it's just cuz I actually found this one on my own, I think putting them in that first empty nook would have been fine.)
Anyway, during level 2, after exhausting all my routes and still not finding anything, I just didn't feel like looking around anymore. A couple of slips into water and I threw in the towel.
Having said that, it's an impressive entry for you first Jam. Certainly a lot more complete feeling than any of mine or other first timers. Very good presentation and use of the assets.
The weapons were cool. The gold disc that ricocheted off walls was my favourite for how OP it was. In a fuller version of the game, it would definitely need to be nerfed with low ammo/rarity. because once I go it, I avoided other throwables like the plague.
Maybe I'll give this one another go when I'm not feeling so sore. XD
EDIT: Other niggles:
- That second pit in the first level kept catching me off guard. Again, if you're deliberately going for a difficult vibe it's fine, but having it in camera shot wouldn't be amiss.
- The upper floor in the first level had a ceiling I wasn't expecting to be there, since it seemed like open sky.
- Pressing X out of Pause should be negated so the player doesn't jump. And pressing start to leave should work too.