Residue is a 2D adventure game played as a side-scrolling platformer. The focus is entirely on the narrative and the puzzle elements are only environment based. It is set in an abandoned excavation site in the remains of the Aral Sea in present-day Uzbekistan, more specifically in the former sea port of Mo'ynoq in northern Karakalpakstan. It consists of twelve chapters, along with an introduction and an epilogue. The Aral Sea was once the fourth largest lake in the world, but due to Soviet cotton irrigation it has become a wasteland. The game starts when Elena Ostrovska and her boss Nikolai Sitvin lower explosives tied to a large package into the excavation site, when a sudden flood causes them to flee upwards, without the chance to detonate the package.
The game then switches between the different characters of which three are controlled by the player, often alternating per chapter. Elena's son Emilio and her husband's father Jumagul Ortiqov travel to the area to find out what has happened to Elena. They soon run into Nikolai who flees from them to avoid the confrontation. The story then often hops through the timeline with small slices and flashbacks shown during regular gameplay where characters who were previously at that location have their conversations narrated and are shown as faded figures. In addition to the story itself there are many optional lore items that can be discovered, providing more context. The chapters have birds at hidden locations that unlock concept art in a gallery.
Exploration is a large game element. Even though the game itself is entirely linear, the environment can often be explored in multiple directions. The controls are limited to movement and an additional key for interactions. Each character has different abilities. For instance, Nikolai uses a grapple hook to move around. The player chooses a direction and swings it. Once stuck, it is possible to climb into that direction. Emilio is athletic, so he can sprint and jump to cross gaps. Both Nikolai and Emilio are able to swim and dive down. The old Jumagul carries a flashlight he often uses to light the environment for Emilio so he can progress. The player can control the direction of the beam. There are many platform elements where the correct route needs to be chosen to progress the story. Some of the characters can reach higher areas, use ladders and can enter doors. Jumagul is also able to boost up Emilio. Even though there are no enemies, there are regular checkpoints as the characters can fall down gaps and die.
The later Steam release carries the subtitle Final Cut and has a number of undetermined improvements over the original game.