I loved this! The game felt great to play, loved the music, the sound effects were superb, the level design and graphics were awesome - just really good all around. I hit a bug in firefox where the player disappeared when respawning, but apart from that it felt very polished.
My only criticism really would be that the map didn't work for me at all (was excited to see that as it was something I wanted to add to my game) and a couple of the rooms felt a bit rough as you moved into them to immediately drop off a ledge (usually into spikes)! But apart from that it was excellent really. It felt quite megadrive-y, and I mean that as a compliment!