Heyy thanks for playing! Glad to hear you've been enjoying it.
I'm guessing you prefer moving with the directional arrows? Unfortunately you'll have to get used to A/D movement since you have one hand on the keyboard and the other on the mouse. (plus I use the arrows and the whole right side of the keyboard for testing lol) If you prefer using a controller, there'll be support for it on the next update tho!
As for the ogre boss... Some people have really struggled with it. My suggestion would be to time your dodge rolls well (with shift, in case you're just jumping to dodge and forgot about it), to see what elements can damage the ogre, and remember the wind arrow uses physics mechanics and can... do things to some projectiles ;)
Don't give up! If you got so far I know you can beat it. Just use everything you've learned so far. But don't worry, the full release will start out easy and take a while to get tough. The demo is just a vertical slice of what the game will be, so the difficulty scales up pretty quickly.