Replace an Array type of the CollidableObjects container with a List (better for removing when collected). Sort everything by their posX, and don't check all of the CollidableObjects in every frame. Start from the last met collectible/enemy and end on the first which is out of the range of the player (basing on his x position).
Replace an Array type of the CollidableObjects container with a List (better for removing when collected). Sort everything by their posX, and don't check all of the CollidableObjects in every frame. Start from the last met collectible/enemy and end on the first which is out of the range of the player (basing on his x position).