Although it's still considered a beta version, the game now boasts sound effects and music via a new synth system which keeps the size of the download to a minimum.
Jason's going to the States for a couple of weeks or so, which means that there won't be any updates for a while, but he's pushed ahead with the project in the past few days (including getting on the highscore hall of fame website for the original Beeb version) so that you have something to play with while he's gone. When he gets back bug (I haven't found any yet) fixes and general tarting up will recommence.
You can get your free copy of ArcCommand from Jason's Website.