Hey, I think you got the beginnings of a cute, arcade-type game here! I can confirm that the HTML5 build does not appear to be playable (isn't responding to keyboard input). Using Haxe with Godot is an interesting workflow I wouldn't have considered. The Windows build is rather huge for the gameplay involved, but it works (I haven't used Godot before, so I'm not sure if this is a typical .exe size).
I liked the pixel art and the simplicity of the style, but I would recommend having more landmarks or maybe a tiled/grid floor because it's sometimes hard to see if the character is moving on a single color background. The walking speed felt responsive and items were spawned with enough frequency that I could easily find them. I noticed picking up some items increased the health bar and some decreased it -- I didn't really know which would do what, so maybe that could be more clear. Is there any way to defeat and/or escape the googly-eyed jelly ghost monster thing? It kind of reminded me of the Abominable Snowman in Ski Free -- it just eventually shows up out of nowhere, lol. If there was some way to attack or do something other than walk, I wasn't able to find the button for it. I'm not sure if the game crashed at the end or if the program just exits when you get caught by the monster, but it was a bit jarring for the window to suddenly close without a game over screen. Anyway, I think it's a good proof of concept for the workflow. Also, nice music loop for a short game! Keep it up!