I really like the NES vibes of this game. I have a real soft spot for these zoomed-out landscapes, where it's a cross between looking at a map and looking at the player's physical environment. Very Zelda II, etc. I played twice and got 2 endings. Not sure if there are others.
I would note that this is the slowest sword swing I've ever seen, although the game was not hard because the enemies are not aggressive.
I would recommend more visual/audio feedback when the player gets damaged. There are many options: a distinctive sound, a red effect to the screen, camera shake, knockback, etc. I know there is a small sound effect, but it's not very noticeable.
Also, a HUD indication of the 3 key objects would be helpful, so I can remember which ones I've picked up.