Outstanding Game!

I love the app, I love the game. I love the challenge. Thank you Brainium. Ive played many games, but have never used any hints. I am still on the lower levels, however, and have gotten my time to 28 seconds on the low and 2.38 minutes on the high. I cant seem to move to the higher level puzzles though. They are too difficult. Should I be using hints. Can anyone share. Thanks.

PAJob about ⋆Sudoku, v2.3.11