IMHO, the ultimate rogue-like game is Nethack.

This is an open source game which has been worked on for decades now by a constantly changing team. It does work over the internet, but is basically a local game, albeit very complicated.

Maybe your students could use the source to get some ideas or solve some problems, or could perhaps build a web-based (Perl-based, of course) interface to a nethack server. The game has had a bit of a resurgence recently due to the recent Halloween occuring on full moon, both of which cause special things to happen in Nethack.

Your project does sound like fun.

drinkd