Remarkable: Completeness as a prototype - I could see this foundation being developed into many challenges/levels, each with the goal of uniting the two characters.
Needs Improvement: I was thrown off/confused by a few things. First, the "button" hint wasn't actually helpful for me because the "buttons" looked more like sewer grates/coverings. "Switch" might be a better word, or making them more visible as interactible items. To be fair, they do stand out, and eventually I figured it out, but I think I maybe didn't step on one properly the first time, wrote them off for a while, and then finally decided to try again and it worked. Also, project and hierarchy were a bit messy - I'd encourage better organization there (folders and empty parent game objects).
Successful: Interesting puzzle-solving mechanics. Although the world doesn't really explain why one player can rotate camera vertical and the other can't, it results in an interesting challenge. It took me a while, but once I figured out that I needed to climb the ramp to shoot the bags I had a nice "ah-ha" moment, which is one thing you might be aiming for in puzzle design, so nicely done!