Reach to the top of the tower to get a strange golden artifact. But be careful, because the tower is filled with a lot of enemies and diferrents traps. 

There are 16 levels in total (which 2 of them are nothing but lives):

Nü = 6 lvls (the sixth one gives you 3 lives)

Lambda = 7 lvls (the seventh gives you 3 lives)

Delta = 3 lvls (the last one is the final boss)