I like the main mechanic of launching you medallion, but I felt frustrated using it because I never could get the hang of it, and never could predict were it would land. I don't know if this is how you see the difficulty in your game, but if not maybe having a way to visualize at least part of the trajectory it's gonna have would help a lot. And then it was a bit more frustrating when I landed my medallion wrong because of that and had no way to get it back, except die and restart all over again. 

I really think this is a cool idea, and it doesn't need much more for it to be really enjoyable in my opinion.

Nice game. Nice music, nice mechanics. I like it.

A few points of subtle critique from my side:
1) The sound for player and enemy movement was a bit annoying. Maybe lowering the volume or removing it entirely would be better
2) I think it would make it better if the player could get medallion back at any time. There were moments when I would accidentally send medallion into a wrong place and would be forced to blink into my death.
3) idk if it was you who actively disabled fullscreen mode, but accidentally clicking outside the game window was quite annoying.
4) mb for the background (which is nicely done) it would be better to change cell size from 16px to 14px to get rid of all those gaps between squares.
5) I think physics can be slightly improved - if you stay still and blink to your medallion in the mid-air, you would instantly start falling due to gravity, which is correct, but doesn't feel right. Maybe adding part of the speed of the medallion to the player speed right after teleport would make it feel better.

Really fun game! I like the medallion concept a lot. My major criticism is that the only option after I've thrown the medallion is to take the teleport. If it lands on spikes then I'm just totally screwed, and that's a super demotivating feeling, haha! And the momentum transfer during teleporting felt a little weird, it didn't always behave like I was expecting it to.
But other than those two things it felt really good to play! Good polish, liked the music, great work!

Oof, this is a difficult game. One of my initial comments is: I shouldn't have to push a button to read the signs in this case (because then I have to guess which button to press, lol). I should just be able to walk in front of it for it to appear.

Other than that, it's a hard platformer, with a mechanic that adds to the difficulty, but does indeed make it interesting. 

edit: Also, it would be nice if there was a way to cancel one of my throws, so I don't have to live with the consequences of wherever I accidentally end up teleporting to.