It took me some time to realize what you meant by "shooting ropes". I was like "What's that black thing coming out the gun? Why doesn't it hurt the other character?"
The idea and the mechanics are cool, and it can be expanded into a great puzzle-platformer with action elements!
Currently, the biggest issue with the game is control. First, the characters are way too slippery; and it's way too easy to fall of the edge. This is especially an issue in this game, since there are two characters. I don't want to worry about the last one while I switch to the other. Second, precise jumping is very hard. The amount of speed you had before jumping effects the jump a bit too much, making it hard to make jumps from a standstill. Also the control you have in you jump while in the air feels very limited.
Once the issues with the control are fixed, I think this would make a great game! The art is amazing, the music is great, the idea and the mechanics are nice... I would definitely encourage you to work on this game after the jam!