Thanks for playing! If you'd like to explore more, I'd recommend thinking vertically ;)
Unfortunately those alpha holes are a limitation of the system this is designed for. Priority (which graphics have transparency and appear in the foreground) is decided on a per-tile basis, and there's technically no true "alpha" in the conventional sense. So, in order to give a convincing 3D effect, the top tiles of objects like the rocks or columns have "priority" (will be shown over the player) while the bottom tiles will not, so the player will show above them. Since the player is 16x16 pixels in size with a roughly 6x7 hitbox centered horizontally and aligned with the player's feet, this works out most of the time, but since the player's hitbox is smaller than an 8x8 tile there will be cases when you're right up against a rock or column where the player's sprite extends past the boundaries of the tile with priority and can be seen "through" the object. This is an imperfect solution but I've chosen to go with it, because the alternative is having the player's hitbox be 8+ pixels tall (which would prevent tile clipping) but that would result in more player frustration in areas which do not have a lot of space to move around in.
The hitbox issues are annoying, yeah. I haven't found a good solution to deal with those yet. The problem is that there's a lot of tools the player can use but, due to this being a GameBoy Color game, there's a finite amount of unique projectiles that can exist in any given scene. I think it's around 5 projectiles. The thrown dynamite and pistol bullets are 2, and I need to save room for potential enemy projectiles, so to be conservative both the fist and knife use the same hitbox. That being said, the hit detection is a bit wonky at times, I have no idea why. I'm looking into fixing it, but as it stands it's not a high-priority issue as the game is 100% completable at this stage.
As for the fists not hitting anything...they actually *do* hit things, and you might be surprised at their range if you ever try punching a pot or something, but they don't do any damage to enemies. Have you ever tried punching a snake? Or a bat? Or a t̴̰̲͔͇͖͗̀e̸̲̊͐r̷͔̬̮͖̩͐r̴̖̜̩͙̂̈́i̶̛̖̲̜̻̲̾͌͠f̶̺̌y̶͉̬̑̾̀͛̚i̸̙̮̕̕͝n̸̟̔͌͑̅̍g̸̬̺̼̟͐͂̅ ̴̧̆e̵̯̩͛̈́͜l̷̛͓̻͔̗̠̆̌̈́d̷͉͛r̶͓͈̆i̸̢̛̩̚ț̶̺͈̀ç̵̢̛̙̆̈́̓ḧ̴̡̛͇͇́ ̴͈̰̏̓̍h̵̪̮̃͛̉͐̓ỏ̶͚̠͗͒͋͝r̷͖͇͙̺̓͜r̶͔̮͊̽̔͌ͅȏ̸̟̲̭̂͛̚ṟ̷̎̕? Not the most effective tool, I'll tell you that. Your fists are useful for some problem-solving elements later in the demo, however, so don't count them as useless just yet!