(Note: If you already have the earlier version downloaded, you may have to choose Update in the pager to get the new version.)
If you are new to BYOND, or an old-timer who could use a refresher course, this is a great place to start. The project was specifically designed as an example of how to build a game with BYOND. I studied it closely myself back in the day, and now I'm rich as Midas! (I'm still here hanging out at BYOND, so that's richness of a sort. The sort of richness that feasts on ramen noodles and egg sandwiches.)
TheMonkeyDidIt also has a bonus gift for you: "anyone and everyone is free to use the icons in there for their own projects (if they have use for a dancing rat or a burping door :))." If you can't find a use for a burping door in a game, I think maybe you'd be more at home at a COBOL programming site, my overweeningly couth friend.