Having the character attached to the mouse is a really cool idea! I'd suggest having a mostly empty level in the beginning to let player's play around with the mechanic, and get used to how it feels. It was a little confusing what the mechanic was, because I would die before I realized the character was attached to the cursor. Also, I think the enemies are able to shoot at you before the level fully loads.
This was a really cool concept, and I'd love to see more of it in the future!