Note: This guide is a work-in-progress.

This will cover the basics of the game, from the controls, to the names of the areas.

Controls
Arrow keys - Move
Z - Confirm
X - Back/skip through dialogue
C - Menu

Honestly, this is pretty simple gameplay wise, note, you can use Enter, Right Shift, and Right CTRL, but those aren't my preferred keys.

Also note, you can use F4 to go into full screen, however, this will cause 1-2 frames input lag, just a warning.

In Undertale, there are three types of endings, first, there's Neutral, these many different neutral endings can range from no one dying, to there only being one monster in the underground, next we have Pacifist, by far everyone has seen this ending once, basically, no one has died, not even one encounter was killed, this is tough, but satisfying, finally, probably the most evil ending, Genocide, again, we've all done this, but not because we wanted to, but out of curiosity.

NOTE: If you do Genocide, make sure you have already done Pacifist, as once Genocide is complete, any future Pacifist playthroughs will lead you to Soulless Pacifist.

In Undertale, if you name yourself FRISK, you'll activate hard mode. Basically, its the Ruins, but the encounters are their CORE-variants, except for a few examples who don't have a CORE-variant.