Bravo! It's just enough exploration and upgrading to be enjoyable without being frustrating. When I wasn't sure what to do next I just went back through old areas until I found a path unlocked by an upgrade. You packed a lot of character into the tiles, even including different biomes (the last was a surprise). The music and sound are top-notch too. I would have liked just a bit more story after the ending, to know the fate of our protagonist.