Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn!
Just a few questions:
How much interaction is there?
Very little as was said above - it's typical euro interaction - someone get something first or takes better place before someone else.
Does it play like any other games?
Other Stephan Feld games or any other game?
How much variety is there in the game environment beyond just different map layouts?
Very much. With different ships powers you will probably never play two the same games in your life.