Fun concept, but having the player invisible all the time is not great, in contrast, I'd have the player be invisible on a timer or near certain objects or having benefits for being invisible like for example passing through some walls, etc, hence, the player can be visible by default and then invisible when needed to hide from guards or pass through walls or solve puzzles and a lot more cool idea,
Also for the moving platforms, the player doesn't move with them, which means you assume you're staying on the platform then realize you died bc you fell off😂
I like the concept, and I think with some extra tinkering this could make for a really nice game,
Also, the art is really good.
the viewport is a bit too big but that's manageable.
Good job!