This was a great game! The ending annoyed me though, not wanting to post any spoilers here but I got the standard ending then spent another hour searching for the good ending (which was a royal pain in the.. umm, a good challenge), finally got the good seed only to find a 5 second ending that I didn't consider being worth the extra time and effort involved.
Also there is a bug where if you re-enter the lava boss's lair you land on the block that sealed the entry off, and the character spins around on it endlessly. This is fixable by pressing R to restart and pressing N to not restart, placing you next to the block instead of on top of it, but could do with being fixed. Other than that, very well made and nicely balanced.
4.5/5, a longer 'good' ending would have gotten you a perfect score but as I mentioned, spending that extra hour on it found me frustrated that it was so short. Would have been nice to have a sequence with The Watcher and The Oracle afterwards.