The spacebar -does- save you.
Generally rope strength is pointless, though, because you want it to almost snap as often as possible, because the first three times you do it it gives you experience. So do it three times, snap the rope on purpose with space when it's not breaking, and press q.
It was alright. I liked what you were going for. It was simple and killed a few minutes until I maxed out the stats and got bored. I certainly wasn't gonna sit here playing an hour just to get the achievement.