can someone tell me how to get the power ups achievement and the riddle…

finsh the puzzel area

i've finished the adventure twice but have never gotten those two achievements. do you mean i need to finish the puzzle mode only?

to get the powerups achievement all you need to do is purchase all the upgrades in the store, make sure you catch all the coins so you can purchase the stuff. not sure on the riddle of the sphinx achievement. completed the game on all difficulty levels including insane and still have not got it. was thinking maybe have to complete all the puzzles without making a mistake but not sure. if anyone knows please post the answer.

* upgrade all items to Maximum

Ecto is correct about the powerups. You simply purchase all the ugrades. You have to complete all puzzle levels to get the riddle of the sphinx achievement.