This worked for me (might need adjusting?)

1. Install bash
1.1. sudo gainroot
1.2. apt-get install bash
2. install freeciv
2.1. Open normal appinstaller and select freeciv from there.
3. Have fun

In case you installed freeciv before you had bash, you need to change bash to sh in those dpkg files previously mentioned. It is not hard job with nano (sudo gainroot, apt-get install nano). N900 keyboard and screen are bit small for this, but you can always SSH to your N900 and do it with putty on your computer. IP number of your N900 can be easily seen with ip number widget or by commandline tools from prompt.