Will Undertale Hard Mode Be Finished?

Hard Mode is an optional difficulty-enhancing game mode, triggered by naming the fallen human "Frisk". Similarly to the Undertale Demo, Hard Mode lasts only until the end of the Ruins.

Can you do genocide in hard mode?

Hard Mode is not a complete game mode.

Even if it is, you won't get any further than the Ruins, because the rest of the game is not implemented even for the Neutral Route.

How many endings are there in Undertale?

Undertale has three different main endings (Neutral, True Pacifist, and Genocide) and a fourth miscellaneous ending (Hard Mode).