Hey for anyone interessted in playing this on Linux:
You need Steam:
- Add the .exe as Non-Steam Game (you have to "show all files")
- Go to the game properties
- goto compatibility
- select "Force the use of a specific Steam Play compatibillity tool"
- select "Proton 6.3-8" (7.x does not work properly)
So far everything seems to work incl level-editor.
(Tested with V0.3.5 Stable)