You know the reason why most of the recent megafauna went extinct? (Mammoths, big birds, giant sloth, saber toothed cat, …)

Just going by your listed requirements: N900 with Maemo Leste.

Of couse its Hardware is to limited for todays tasks (Web)

This is the same effect which makes piracy beneficiary for developers. The EU financed a big study on it, expected to confirm claims that i causes high losses for creators. After they got unwanted results they shelved it silently. The Pirate Party then brought it to light.

Free advertising is always good and many people who have a no hassle option to own the game and to reward the creator will do so.