The caracter is a bit too floaty for my likings but overall a real nice and shor game to pass time

Awesome

cute but too short

and the lack of any moment of invulnerability (or at least mobility) when taking damage makes one point of damage = almost inevitably followed by a couple more and death.

don't like that one bit.

Fun little game. Would love to see it fleshed out into a full game. The graphics are blocky but cute and I like the multi-layer parallax effect in the background.

Some suggestions for your next version:
Baddies need proper death animations, even if just a frame or two. The shrinking thing breaks the retro pixel look.
Like most other games, player needs to go invincible for 2 seconds after getting hit. Otherwise it's too easy to get pinned and killed by multiple quick hits. That makes the hearts useless.
Fire should heal all at once. Why do you want to make me wait for the hearts to fill up? At first I thought you could only get 1 heart per fire, didn't realize I could wait for more.
Dialog box - When you're near the talking woman at the beginning, or a sign, or whatever. It would pop up at the top and tell you what it says. Not one that you have to click OK on, because that's annoying. Just one that passively pops up with the message when you are near a readable/talkable object, and disappears when you walk away. Could also make it pop up at fires, say "Rest by the fire and heal yourself" or something like that.
Better waterfall animation - You've done a great job with the graphics, and not making the game look tiled. But the waterfall animation breaks that, looks very square and tiled.
The height you bounce when jumping on a rock is inconsistent - sometimes throws you way up, sometimes just a few pixels.
If you let it sit at one screen, the game eventually starts slowing down. If you manage to get to the next screen, it's running fine again. I'm guessing you've got some kind of coding leak.

The game is super fun until the boss battle because of the drawn out section at the begining that doesn't add anything and is unskipable.

Didn't finish.