This small set of maps is pretty fun, and the compact nature of them provides a refreshing break from the sprawling maps we had received in 2.1 times. Like Jood said, it's a solid, fast, and fun set of maps that worked great and felt just right in the 5-minute playtesting sessions.
There are a few things I'd like to point out though - Super Ring Monitors should be placed around the maps to provide players with ammunition. I've noticed a few Ring monitors that become Weak Random Monitors when popped, and those are generally for shields. Some of the maps have multiple Strong Random Monitors which is not ideal for a map of this size. These maps would benefit from only having one SRM in each map.
General rules of thumb, Ring monitors should stay Ring monitors and be placed in accessible places to provide ammunition. WRMs should be placed every so often to provide powerups and typically start on Elemental, Whirlwind, Force, or Super Sneakers. The SRM should be placed in a hard-to-reach area that all characters can get to (the map with the pillar in the center that has a room in it is a great example of a good SRM spot), and start on Force, Whirlwind, Elemental, and maybe Attraction. On the plus side, you have good Infinity and weapon placements in general.
The open-ness of certain maps prevent the Bounce and Grenade rings from being generally useful, and Metal Sonic is also quite powerful because he can accumulate speed fast and maintain it. However, this is something that all the open maps, including Meadow Match and Jade Valley suffer from, so I wouldn't worry too much about it.
Anyway, despite what I had to say above, this set of maps is still pretty solid, worth a shot, and a good time killer if you want to shoot your friends in the face.