@shirogane
here picture to lvl 23:
http://img687.imageshack.us/img687/8458/nowyobrazmapabitowa3d.png
Create portals on points 1a and 1b. Wait until plasma go through 1a to 1b, then shut both portals IMMEDIATELY(or plasma will go back through portals). Quickly put first of portals on point 2, and second in reachable place and teleport to button, push button to open door and have hope that plasma don't explode before it reach destination or you will have to do everything again.
@Tukkun: Why one of coins in Ultimate Avoidance on Impossible difficulty was on that what I have to avoid? It maked it impossible to catch me because it was catchable too late for my reaction xd
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