It was fun and an interesting idea and there is music and sound effects(although could use some work like placing platform give like a brick sound effects),as for the controls, am I suppose to be able to double jump cause I can with combining both space and up keys, the art is simplistic but there is a lack of animation in fact there's is none(like the player getting squish while jumping or the platform increase to it's normal size while being place), the jumping particle effects would be better for it to slowly decrease in size and disappear
fun and simple game good job :D