You've clearly put a lot of effort into improving this since the first version I saw on NG. I couldn't find any bugs in the game play. It's much more enjoyable now that you're not in fixed motion. I really like the visual style, it reminds me of games I used to play back in the NES/SNES days. I'm quite impressed with this game. Seeing as this is still considered a beta in your description I can't wait to see the final version. I have a few small suggestions. I can't seem to figure out exactly what dictates when a level ends. I'm not sure if it's reaching a certain depth or killing a certain number of enemies. It's not a big deal but I think it'd be an enhancement to be able to tell either how long a level is or what you need to accomplish to finish a level. It took me a couple tries to figure out that the green door in the shop was the exit. If the guy tells you I might have missed it. If he didn't I'd suggest that you either put an exit sign on/above it or have the shop-keep tell you it's the exit. I quite like the music and sound effects, they feel quite nostalgic to me, though a mute button might not be a bad idea for those that like to listen to their own mp3s/music while playing games.
All in all this is turning out to be a great game. I really look forward to seeing the final version and future games from you.