why this game stuck when i upgrade the weapon

I finish off all the enemys ont he level, complete the secondary objectives, and get the boss down to 0 health, but the game doesn't trigger the next event. I would asume it would be like the first boss... the level ends and the game asks if you want to proceed to the next level....

Hi, I would like to translate your game to my language (Portuguese-Brazil).

I buy this game in key type, and this game is very laggy, can i get my money back? This game is very very laggy!