Great art style! Jump controls confused me. Aim felt annoyingly inconsistent, and I'm not sure why. Could you draw dark line showing the arc the arrow will travel before we click the mouse? I think that might clarify some things to the player.
If the biggest strength is the art style, the biggest weakness is that, ultimately, there's no goal. Nothing to gain from killing enemies, you just avoid losing until you get stuck on the fence at the end and then end up losing anyway.
I feel like there's lots of potential, here. You're knocking the aesthetic out of the park! Just add some gamification so players are building towards a goal. Collect monster souls and use them to buy better bows, so you shoot to break doors, to get into new areas where there are tougher monsters that drop bigger souls, so you can buy stronger bows... that kind of thing.
Maybe some world lore, or a little more personality for our archer, if time permits. But deeper gameplay comes first.
Watch this space, folks. If this was just a quick art test, there's no telling where the Brothers Calice might take it from here!