Yes it's possible to change the richness without losing all archivements. It's still cheating though :) Can't give the most specific steps to do it right now but it's something like this. Go to the location of your save file Unpack/extract/unzip your savefile. In you unpakced savefile open control....

thx

Hi all,
just new here, bought the game last week and had some nice hours with it!
I have read about a sandbox-mod(us) but don't know how to start it,
can anybody help me, please?