Cool to see a run'n gun with H content! I made a couple of prototypes with similar ideas and I was wondering why there are so few of games like this. I'll be watching this closely!
I somehow disagree with that. If your game is meant to reward the player by losing ( which is perfectly fine in an H game ), it doesn't need to be tough and therefore can easily be played 1-handed. People who believe that haven't tried hard enough or simply don't know about key mapping.
Anyway, your game has very good ideas and I hope you will go as far as you can for it. What game engine are you using btw? I'm guessing GMS but not sure.