Use WAD to move. K is melee attack, L is ranged (once you unlock it), and S is a down attack (also once you unlock it). There is a shop level every odd multiple of 10 (EX 10, 30, 50, etc.) and a boss on every even multiple (20, 40, 60, etc.). After a boss fight, the 'area' changes. The rest is self explanatory.
