Ah good to know. Yeah I've heard about the zero bird level 3-5 but I haven't been able to do it myself. How long after restarting do you have to wait? I've been waiting until the top green pig stops moving but the most that has happened is the top right gray beam falls. That's it.

And yeah I think 8-6 may be zero birdied too but the first bird can be worth more than 10k because of all the potential ice to break. There are alot of ways for the tower to fall though, so when it does, you have to hope for a favorable one.