Or, go to the settings of your N900, go to Text Input, Change the Keyboard Layout to English, go back to the game.

Start playing using the 4 Coursor keys, as soon as you're able to pause go to the designated menu, select the down entry, press [CTRL]+[Backspace], go to the Language settings, switch to french, go back to the game and assign a botton, at example [S] for down. Repeat it until you have a for your working keyboard setting.