I briefly owned this for 40 minutes of gameplay, at which point I hit a fatal bug: on OSX 10.11 I could not interact with the dialogues. Which meant that I could not get past the second level. Up to that point, it had been a very challenging (but unimaginative) game: levels are fixed, enemies spawn in the same place if you die and behave the same, so it's more of a puzzle - what do I need to do to defeat these - than the action RPG I was hoping for.