Go! Sudoku

The addictive game comes to the PSP.
Those of you in the know know exactly what Sudoku is about. It's an ancient numbers game created to challenge and feed the brain.
You are supplied a Square Grid with 9 small squares from Left to Right and 9 squares from top to bottom.
The aim is to get the numbers '1 to 9' within the grid without repeating a number in any Box, Row or Column.
It's sounds complicated but it's not. It's just hard to explain with words.

There are 1000 grids available. Rangings from Easy, Mild, Hard and Fiendish. More are available to Download online.

Unfortunatly though you can't lose. Whenever you enter a wrong number the number turns Red which means that it's placed wrong. Also if you use up all the 9s for example the option to place a 9 disappears.
Another thing that bugs me is that you never feel rewarded for passing a grid simply because the game practically tells you the answers. It is true that you get a time penalty if you enter the wrong number a few times but who cares?
Every grid has a Target Time but if you beat the target time nothing happens. You get no rewards or even notification that you beat the Grid Record.

This could've been a great game but it was ruined by the game telling you if you've placed a number wrong.
They should've made it exactly like doing a grid from the newspaper with a pen. The ink in my pen never turned red when I made a mistake. Why they added this ridiculous feature is beyond me. The whole point is to learn from your mistakes and correct it later when you get stumped. That's something that can never happen in Go Sudoku.

This had the potential to be a great puzzle game but instead we are left with an okay puzzle game.