I like Cuphead a lot, but I think it’s better enjoyed if you know a few things before you play. I’m still writing a lengthier beginner’s guide, but I want to immediately provide one humongous tip: Remap the controls before you play.
The default controls are, in a word, bad. Jump, shoot, secondary fire, and dash are all assigned to face buttons. I spent most of the game with the tip of my thumb holding down fire while the joint crunches jump. Keeping my thumb in place while dashing into a secondary attacked required finger acrobatics and contortions not meant for the average human hand.
The good news is the game allows players to remap controls however they feel fit, and I found a really natural solution. Enjoy!