Since the developer welcomes feedback, here is my shoddy review, :P:
I was one of those who was scared off by the map-less zone, but thanks to Gridmonger I worked through it, got past the library, and overcame the final boss. Navigating without any aid was how I managed to map the library shifted and rotated, despite the fact that the manual does give the hint required to get the right orientation.
Now, MM0 does various things that aren't my preference, but are perfectly cromulent design. Nevertheless, all things combined, I've found that combat and puzzles become less interesting as the game progresses. Damage spells are too powerful, and buff spells—once full-party spells become available—are streets ahead of debuffs. With rest-in-dungeon design and the low level cap, it soon becomes better to run from the vast majority of combat, use two all-enemy nukes—even if Greta doesn't have the staying power of Fizzy, and clean up with standard attacks. Rest and repeat; the random encounters with debuffs aren't enough for the awesome power the party has at high levels—the strong healing doesn't help either. Then, the last floor wasn't very challenging due to the auto-map, amusingly enough.
Overall, it's my impression that MM0 would be a good first blobber, but it is "skip-able" for the experienced player, even if I enjoyed my time with it. Its short length and quick start are its greatest attributes.