Hello! thank you for your feedback =D
About being locked, yeah unfortunately I just add the Medium and Hard Level two days ago (VERY BAD IDEA) because some people found the first demo too easy and I didn't anticipate that this situation it could happen. Really sorry about that... It really messed the first experience of a lot of people :'(
I just posted a new build with no hard mode and a rebalanced medium mode. I will try to fix the problem asap at a deeper level very soon to make it more fair and engaging for the player, someone already suggests me a very good idea, it should be done in the next couple of days.
About the keyboard mapping, I'm sorry about that too ^^, I always play with a controller so I didn't really know how to map them. I just had a lot of feedback on it, I'll change it next week fore sure. But the controller should have worked thought :/ It is possible that the layout is only displayed if the controller is a Dualshock or a Xbox controller, but technically, you can enter the game and still play with the controller, you just have to figure out the controls during the tutorial. Did you tried with a PS or Xbox controller or one from an other platform?
And in general, I will improve the game on many points. I'm solo on it so I just had the necessary technical feedback before the demo was released, but not a lot of "real players" played it, so there were a lot of things I wasn't aware about. Also I took time to polish some things, but there are also things I just let in their "just working" states. I'll do my best to make it better very soon!
Again, thanks a lot! Hope you'll get the chance to retry the demo in the future :)