Undertale modders repurpose obscure free Steam game for online co-op, triggering 1,700% player spike

Crashphalt, a free local-multiplayer fighter released on Steam in 2018 by developer RetroSpecter, saw a 1,700% jump in player activity after the Undertale modding community found its files could activate Steam Remote Play for the "Undertale Together" co-op mod. Undertale lacks native Remote Play support. Players copy Crashphalt's files into their Undertale install folder to enable online sessions. RetroSpecter learned of the surge only after noticing the player-count spike.