I liked NES aestetics: sounds and pixel art pallets. The title screen reminded me of Ninja Gaiden. Music is wonderful, and very fitting, good job.
A couple of issues in my opinion - are that although you have a health bar, most on the deaths are one shots from lasers, spikes or ladders. And normal enemies can be tanked, because there are lots of health and bonuses.
Also, I ran to the left at the beggining of the level and fell off the world =)