A new update to Diamond Caves is available:
Version 5.0.4
I will post a Steam Guide for the Level Editor within the next days, I am sure there are a few questions on how to do certain things. To start the Editor, right click on the game in Steam and select "Start Game Editor".
You can use the Editor to create your own levels, download new levels from the Steam Workshop or import old Diamond Caves 3 Levelgroups.
If you have problems with game stuttering please try combinations of game speed and vsync.