Interesting proof of concept, but needs a lot of w
First, off, when asking users to use the mouse, also allow them to move with the WASD keys. IT should also be possible to jump with 'W'
It's also impossible to tell what objects you can interact with before you interact with them. You can't distinguish objects in the foreground from objects in the background from objects that damage you, from objects that you can move. This may seem artsy to you, but it will confuse the player(in a bad way) and it will make the game less fun.
Secondly, I found that the ONLY challenge in the game, was identifying which objects I could interact with and how. The first level, as painfully simple as it was, was the most difficult. because you had to jump gaps.
In the second level, I found that I was able to tediously carry myself through the entire level on a single platform.
In the third level I held down the right key, and jumped at appropriate places.
I don't know what the collectible Items were for. I don't know what the HP bar was for, I never lost HP, there was only instant death. Your user shouldn't be asking these kinds of questions. IF you're not using the items, for anything, then exclude them. When you decide to do an update which uses them, than you can put them back in.