Waterfall is Undertale's third area and middle point, following Snowdin and the Papyrus boss fight. The following is designed to be played as part of a complete Pacifist guide - in short ...

Hotlands is the fourth major area of Undertale, following on from the Undyne battle and Waterfall area. The following is designed to be played as part of a complete Pacifist guide - in short ...

(on PC you use arrow keys, not WASD to move). In Undertale you will make your way through different as you try to escape the Underground. The first area you'll encounter is the Ruins.