Ok i cant achieve some of them, ive already defeat god mode, perform a shotgun combo, and the game doesnt give me the reward or mark it as done. By other hand, the perfom a stomp combo achievment was getted but the reward not.

May i suggest logging out and logging back in again as it could be a lag issue (refreshing the page).

Did the achievement flash up while you were battling, Did you win the battle when this event occurred as that could be a reason why you didn't get the achievement, Have you looked at the completed achievement part as for the stomp achievements it goes up from 1 to 10.