Thank you for your feedback! I really appreciate it. I wanted to add a sprint or run button but I was worried that would lead to players then running either straight to the boss or when detected, easily escape from the enemies. Something to test with for sure.
UX is a work in progress and I completely agree about an indicator giving players feedback on when they can climb or assassinate a target. I had these things planned but unfortunately ran out of time. I did not think about making the area wider though, that would be a very smart decision. I often found myself trying to find the 'exact' spot the rope was so I could climb it. My wife's playtesting had the same result.
Level 4 was a tough decision choice. I wanted to try and make a level that was more immersive and somewhat reminiscent of a Splinter Cell game, climbing up a building with multiple floors. I agree with the gaps in the beams and I am already trying to find ways to identify where the gaps are. Especially the first gap you come across, that one seems very hard to spot.
Thanks again for your feedback and thoughts on the game!