Just snagged it from the Humble Bundle and had a thoroughly enjoyable levels 1-15. At 16 it became impossible. I've spent hours trying different scenarios, looking up strats, etc. I'm placed in a very weak position with very strong opponents with no opportunity to gain strength. Tried levels 17-20 and it's the same. Weak start with crushing opponents. I'm playing on relaxed mode...this is not relaxed; it's sheer frustration. Had this happen many times with various Android games...great fun for awhile then difficulty goes through the roof.