I love everyone's creations! Some of you have done stuff that I wouldn't even know where to start on.
Here's the latest progress:
A life bar has been added! You lose life constantly over time, and if you collect loot it replenishes your life. Keys and locked doors have also been added.
If you take damage while you're holding a key, you lose it and have to re-collect it. There can be up to 3 keys/locked doors per level, and you can hold 3 keys at a time.
Next I'm probably going to look at adding some real enemies to blast!