I made this same mistake on my game, people will be sent to the jam version of your game's page which hides any descriptions. I happened to go to your jam page by mistake and that's how I learned the controls but for most they will just have to figure that out. Also, without reading the game's description my goal would have been confusing.
Not entirely sure what happened after the timer ran out other than a bunch of shadow monsters coming for me. Assuming I was meant to beat them, it would have been nice to be able to hit more than one at a time; if I could hit multiple at a time then the attack hit-box may have just been small, not sure.
The sword sounds felt a bit weird sounding the same regardless of whether you missed; this was more of a problem when there were a lot of enemies and I'm not sure if I hit one or not.
The art was fantastic. The ambient sounds were nice. The controls made sense.
Overall, a nice jam entry.