Attempting to play the game in the browser WebGL panel, I was able to get to the control display for shift and ctrl. The play AND quit buttons became greyed out and the menus stopped responding so I gave the downloadable version a try instead.
Music's on point. Good job on that.
The inability to slash while the shuriken is airborne is very strange to me. It sort of feels like you are forced to warp if you want to use spells. Maybe practicing at the game will make this feel more natural for players, but while I'm learning the controls it feels easier to just not use the shuriken in combat.
Putting dash on C meant that I simply wasn't able to use it while moving with WASD. Perhaps I am just baby idiot noob who needs to get good.
Z / X / C as default inputs is painful. I'd recommend putting them somewhere like Q, E, R, T, or F so that they're within easier spiderhands distance from WASD while moving, or assigning them to keys like J / K / L / ; so that players can move lefthanded and input righthanded (in addition to arrowkey input righthand and zxc lefthand)
Being able to shuriken out of the map is pretty OP. The doors seem to correctly block shuriken OOB glitch so hopefully the next demo treats walls that way too.
Enemies popping into existence as you enter a room is neat but could use a little bit more polish and fluff so they don't just immediately jump you.
I like the pointy screen transition on level exit, that's pretty neat.
Some SFX or manual-interact to open chests might make that a little more visceral. It seems that the item you get from the chest is dropped onto the ground in the same spot each time, too - it may be better to simply drop the item on the player and display the pickup over the player's head or something. Right now running into a chest then having to run a circuit around the chest to pick up what was presumably inside it feels a little raw.
The control /tutorial screen seems to be finnicky about which controls it shows based on whether or not you are using KBM or a controller.
Volume controls / options menu would be cool.
Visual clarity is pretty good but the brightness in some areas made it kinda' hard for me to tell what was what when it was all moving at once. I'd recommend taking screenshots of the game and reducing them to grayscale so you can see how bright things are relative to one another. It may help make the action more fluid in more difficult areas later.
Overall has promise, very fast paced though. Needs some kind of tutorial to familiarize with the movement mechanics and allow players to learn how to effectively move, because the current difficulty curve is "welcome to the real world" which might turn off a lot of players.