So you wake up, not conscious of anything weird, but then, you know there's something different.
Then you see these metal disks. Those weren't there before !
You turn around. A huge key, about 100 meters long shows up. It wasn't there before !
Oh no, it happened again !
Someone built a huge door around you and you are stuck in the lock !
You're only hope is to unlock this door so the key will fall out !
To do so, make all dots green. Every metal disk has 4 gates, they can be either open or closed. Green dots mark which gates are right. Red dots mark which gates are wrong. Entering a metal disk will make it rotate 90 degrees clockwise.
Use the arrows to move. Page down to undo Page up to redo + to go to the next level - to go to the previous level