There are collection of small puzzle games:
http://www.chiark.greenend.org.uk/~sgtatham/puzzles/

They compiled without any changes for N900. Only one of 27 games needs two button mouse, all are very playable. Some uses keyboard, which might be better to implement some other way.

In this page, there are FreeRunner port, which uses launcher, so it doesn't add 27 new icons to application menu:
http://om.edorfaus.info/sgt-puzzles/

So, who wants make and maintain this port?