Thanks for taking the time to try out my game! Glad you had a generally good experience.
You brought up some really good things that I am definitely taking into consideration.
1. A tutorial level is definitely in order. That will certainly help clear up some of the initially confusing mechanics.
2. I already have a checkpoint system for my linear style levels, however the more open format ones (such as the key collecting level) could definitely use some refining. Perhaps every time you collect a key it remembers it if you die, so you aren’t having to go back to square one each time.
3. I’ve already been thinking about a collectible element (3 big coins or 3 diamonds) that the player will have to explore more to collect. So that is a good callout.
4. Will be pretty easy to adjust the overall speed of enemies so they don’t feel like bullets darting around.
Hopefully you will check back as this progresses to see what you think! 😉
Thanks again for your time!