Games like Fundamental
Fundamental leans idle. These games share the most with it, and each one says why.

Incremental Mass RewrittenUpdated
Also pure numbers, prestige, physics · Same active/idle balance (leans idle)
Gain mass, become a black hole, then an atom, then a supernova. The numbers get absurd quickly and never stop.
4.5★ galaxy60% idle
Distance Incremental
Also pure numbers, prestige, physics · Same active/idle balance (balanced)
Go faster, go further. Rockets, time reversal and a very long list of layers from the Prestige Tree author.
4.4★ galaxy55% idle
Antimatter DimensionsUpdated
Also pure numbers, prestige · Same active/idle balance (balanced)
Buy dimensions that buy dimensions, then break infinity, then break reality. The reference point every numbers-go-up game is measured against, and it has a real ending.
92% steam4.6★ galaxy200–600h ending55% idleIncremental Mass: Classic ReloadedDormant
Also pure numbers, physics, prestige
A reloaded version of the classic Incremental Mass, where you grow your mass through layered resets.

DodecaDragons
Also prestige, pure numbers · Same active/idle balance (balanced)
Twelve dragons, twelve colours of magic, and one of Galaxy's most-favourited games. Big numbers, handsome UI.
4.5★ galaxyhas ending55% idle
Revolution Idle
Also pure numbers, prestige · Same active/idle balance (leans idle)
Wheels inside wheels. A clean, abstract prestige stack with a lot of layers and very little fluff.
87% steam60% idle
SynergismUpdated
Also pure numbers, prestige · Same active/idle balance (leans idle)
Five prestige layers stacked like a tower, each one reshaping the ones below. For people who liked AD and want more.
76% steam60% idle
The Prestige TreeComplete
Also pure numbers, prestige
A skill tree where every node is a prestige layer. It spawned the Modding Tree and a thousand descendants.
4.6★ galaxy30–80h ending50% idle
Incremental Adventures
Also prestige, pure numbers · Same active/idle balance (leans idle)
Heroes fight on their own in automated turn-based combat while you tune the automation and push toward double-exponent numbers through stacked prestiges.
78% steam70% idle
Underworld Idle
Also pure numbers, prestige · Same active/idle balance (leans idle)
Run an underworld where higher units spawn lower ones, across four factions each producing its own resource, with a prestige system.
71% steam70% idle
Idle Research
Also prestige, pure numbers
Research and craft flasks and tubes to generate three kinds of energy, with several prestige types, fights, skills and potion brewing.
85% steam50% idleSwarm SimulatorDormant
Also pure numbers, prestige
Grow an alien hive: larvae, drones, queens, nests, and then the numbers start producing numbers.
80% idle
Exponential Idle
Also pure numbers, prestige · Same active/idle balance (leans idle)
A math idler where the upgrades are literally terms in an equation. Graduate, then play the custom theories.
75% idle
NGU Idle
Also prestige · Same active/idle balance (leans idle)
Joke-dense RPG idler with dozens of interlocking systems. Beating a boss is the easy part; allocating energy is the game.
96% steam65% idle
Tower Ball - Incremental Tower DefenseDormant
Also prestige, physics · Same active/idle balance (leans idle)
Place turrets that shoot down falling balls for cash, upgrade seven tower types, and prestige to restart stronger on harder levels.
61% steam75% idle
Zen Idle: Gravity MeditationUpdated
Also physics, prestige
Upgrade physics-driven balls and stages for income, collect cards for permanent bonuses and prestige with evolving perks, playing passively or with strategy.
50% idle
Idle Gumball MachineUpdated
Also physics, prestige
Fire gumballs into spinning gears in a plinko-style board, buy upgrades for explosive number growth, and ascend to trade everything for stronger bonuses.
91% steam25% idle
Cookie Clicker
Also prestige · Same active/idle balance (leans idle)
The grandma of the genre, literally. Click a cookie, buy grandmas, ascend, and discover the game is much stranger than it looks.
96% steam70% idle
Idle SpiralUpdated
Also prestige, pure numbers
Grow a mathematical spiral ever outward by buying formula upgrades, stacking several prestige resets, and use the spiral as a weapon in battles.
79% steam
Unnamed Space Idle
Also prestige · Same active/idle balance (leans idle)
A ship, a sector map and a tidy prestige loop. Quietly one of Galaxy's most-played games.
92% steam4.5★ galaxy70% idle
Omega Layers
Also prestige, pure numbers
Buy generators, clear challenges, and prestige up an endless ladder of Greek-letter layers, like Antimatter Dimensions with no cap on layers.
4.1★ galaxy
Clicker Heroes
Also prestige · Same active/idle balance (leans idle)
Click monsters, hire heroes, ascend, transcend. The game that made idle RPGs mainstream on Steam.
90% steam60% idle
Exotic Matter Dimensions
Also pure numbers, prestige
A big-number incremental inspired by Synergism and Antimatter Dimensions, set in an eight-dimensional universe.
4.1★ galaxy
Shark Incremental
Also prestige · Same active/idle balance (leans idle)
Grow a shark, eat fish, go deeper. A shiny, fast, well-paced modern idler.
4.5★ galaxy60% idle