Random Hero Defense

This game is Random Hero Defense.
You summon units with goods.
The units you summon are classified according to certain probabilities.
Of course, the higher the grade, the harder it is to obtain, right?
Collect these units to defeat enemies that become increasingly stronger each round.
If the enemies destroy your building first, you lose.
Summon the best units to block waves of enemies and defend the building for up to 30 rounds!