Waterfalls and floating islands are just a taste of what’s to come.
So far, Terraria has been having a pretty good week. It became the first title in a long time to outsell Mindcraft on Xbox Live Arcade, and has had a fairly good launch otherwise. Developer Re-Logic talked about Terraria getting some new features for the PC, and recently some screenshots have been posted on the official Terraria forums indicating the same.
Terraria is an open world game just like Minecraft. It is randomly generated and one can build anything out of nothing, while defending against random monsters and exploring even more random areas. It diverges from Mindcraft by taking place from a 2D-side scrolling perspective.