Iron Soldier II cart has always been a limited edition, although they don't seem to have any intention of discontinuing availability as long as there is interest in it
I forgot about that (and was too lazy to pull my cart out of the closet), but I guess any game could be considered "limited" to some degree.
Telegames UK typically has these games available. I see that they now have the Iron Soldier II cart listed as a limited edition, but I don't know whether that is any different than the cart version they have sold in the past. Whenever they run out of any of the Telegames releases, they always seem to obtain or produce more.