I had previously only known Russian Railroad and to check out the new variants I started a solo game (player number is given from 1-4). However it seems the solo rules are not implemented from the rule book I gather some actions should be unavailable (as in the two player version additionally also the gold action and player order actions). Also a simulated opponent "Emil" is supposed to block random actions during the placement phase. Playing solo with everything open is pretty wild my first try on the Asian map ended with 700+ points 