I liked it. I think a good maze level should be a bit... twistier, though. Not necessarily longer, just a bit more puzzling.
The transition from the first screen to the second was too abrupt, I think. Also I thought getting the climb power-up was a bit too tricky. It could stand to be just a bit lower. I also found getting past the shooter on the screen with the locks pretty hard, even after I had taken care of the spider. You might want to put a less random enemy there.
Other than that, the level was great! I really liked what you did with the tileset. It had just enough variation to give each area a distinctive "look", while still making the level look consistent.