Great Concept, but it's ruined by the developers money grubbing ways. Was tolerable, especially after they started giving you more gold. However, recently they released an update which requires 10x the unit shards to get the units to the same relative level, units used to progress from lvl 1 to lvl 15 for instance, now it's lvl 1 to lvl 150 to be the same power, and the shard cost is not lowered to balance. DISGUSTING! Pay to win, steep prices too for very little :( I am a long term player btw.