Hey, thank you very much! I'm very happy you enjoyed playing Decline's Drops. As for the tutorial, for now you just have to restart the game, as there are no real saving system yet.
As for the "super punch", it's badly explained, and I apologize for this. You have to run for a certain amount of time. You'll hear a specific sound and the character will start to flicker. All you have to do is now pressing the attack button!