Wow, this is not your typical platformer! Very creative concept and I love how the monster also acts as a health-meter.
The levels can certainly be challenging but even if you die the game seems pretty forgiving (as long as you don't die too many times in a short timeframe). I got as far as the level with the arrows and had collected about 4-5 items. It's also cool how each of the levels is different and presents new challenges on your way back.
Some of the traps are very sudden and unexpected so you usually die on those, but as mentioned before, the penalty for death is not too bad as long as you don't make a habit of it.
I wouldn't call this game hard, but I wouldn't call it easy, either. The challenge was very well-balanced.
Being able to play this in a browser was also a nice feature.
I didn't encounter any bugs.
Recommended!