Definitely an interesting play, it sorta has that... I guess speedrun -esque style, at least to me.  Especially since the "Plagued" blade (or cursed not sure which based off the end) ups your speed and gives you access to a dash.  Personally it was way more fun to just attempt to beat the levels under a hard time limit from the sword and with the speed and dashing. 

Some quick feedback though:

• The level design while mostly simplistic is interesting and definitely has a lot of that "speedrun" feel as I said before.  It was interesting to do what I could to beat the level as fast as possible.  Even without a timer.  So a personal recommendation would be to maybe lean into that, add a timer go for the speedrun style stuff and see what happens.
• The fact you can put the sword away kinda removes the danger of it, since you can essentially just grab it, dash, put it away, grab it, slice etc..  I feel like it could be an interesting speedrun style puzzle kinda thing.  Where once you pull it out you can't put it back.  Heck you could possibly (and this might be weird) add some sort of zoomed out view before you pull out the sword where you can look around the map and see where everything is at.  Then when you hit Q to pull it out it brings you back to the character and runs a slight animation or something to give you a moment to adapt to the camera view.  
• Movement feels a bit... I guess "floaty" the deacceleration of the player is a bit too slow so it's hard to stop exactly when you want to which led to a lot of accidentally going off the edge or into an obstacle depending on where I jumped from.  As well when you are in the air there were a few times where that on top of the air control comboed and cause even more missing platforms and going off the edge.  So just a bit of tweaking on the deaccel and the air control could help this possibly?

Overall though this base idea seems interesting and I got pulled into attempting to run the levels quite fast when I was playing through it.

This blade... it looks familiar...