Notes:

- the following levels were fixed by Niko Bhm to be solvable:
  * 011: exit added
  * 030: sand after yellow EM gate removed
  * 034: blue key added
  * 071: sand after yellow EM gate removed
  * 096: blue EM gate moved left one tile
  * 100: sand after yellow EM gate removed
- all tapes recorded and provided by Niko Bhm
