The concept of your hero being invisible is a great one, but the execution of the mechanic is very important. As it stand, I don't know where I am at all unless I'm attacking! All the enemies know where I am, but I don't :( Having consistent dust trails behind the player would help (I saw them sometimes, but not always). The combat mechanics were a bit confusing too, I couldn't get the sword to attack all the time -- as though there was some cooldown I couldn't figure out.
Let me ask this, what would be different about this game if the player were visible? Are there game mechanics that don't make sense if the player can be seen? I couldn't make it too far in the game, but from what I played it seems like the player being invisible was of no consequence except to frustrate the player. Mechanics that are worth exploring:
1. Lack of motion should make you truly invisible to enemies.
2. Differentiate walking which is silent from running which makes noise.
3. Make sound in one place as a distraction so you can sneak by somewhere else.
4. Have mechanics that reveal the player temporarily (like dust / water falling on them).
Lean in to your core mechanic!