I played the Atari 2600 Space War this weekend on an Intellivision with the Atari 2600 attachment. This is such a good game!
I tried finding a good one for Linux, but the only one I found, KSpaceDuel, is way too complicated and it got a few gameplay issues compared to the original one (the energy and damages are displayed as numbers rather than some visual widget, please!).
If you know of a good Space War for Linux, write me at firstname.lastname@example.org.