Games like Idle Army
Idle Army. These games share the most with it, and each one says why.

Archer Forest : Idle DefenseUpdated
Also idle, merge, combat
Defend a forest with animal archers by merging arrows into stronger ones, clearing stages, and beating bosses for loot.

Merge Gun: Shoot ZombieDormant
Also merge, idle, combat
Combine identical guns into stronger ones and use them to hold off waves of zombies.

Marisa!ReturnTheBook!
Also idle, combat
A Touhou fan game where you craft Shanghai dolls styled after Gensokyo characters to storm Marisa's house and recover her borrowed books.
90% steam
Slimeward
Also combat, idle
Turn a slime that landed outside your house into resources, building up a village and recruiting heroes strong enough to beat it.
89% steam
Pacifish
Also idle, combat
Fish six areas, fight back against what you disturb, hatch and eat fish for stats, and craft poles, playable idly or actively for speed.
84% steam50% idle
Alien Invasion: RPG Idle SpaceUpdated
Also combat, idle
Guide an alien that eats humans to grow stronger, evolve its abilities and beat bosses in new locations.

Battle Royale Tycoon Idle GameDormant
Also merge, idle
Slide and merge weapon tiles on a grid to build a battle royale arsenal of hundreds of weapons.

Battle Simulator: Idle WarfareUpdated
Also idle, combat
Recruit fighters from many eras, from Spartans to helicopters, and watch them clash in automatic battles.

Blacksmith - Merge Idle RPGDormant
Also merge, idle
Merge weapons into over 81 new designs, use runes to multiply gold and duplicate items, and reset for Soul Gems when progress slows.

Blade IdleUpdated
Also idle, merge
Turn a herb collector into a sword hero, clearing stages and dungeons and merging gear to power up.

Candy Critters: Idle MergeUpdated
Also merge, idle
Buy and merge cute critters that chew through candy blocks to uncover coins and treasure across a sugary world.
75% idle
Cat Hero : Idle RPGUpdated
Also idle, merge
A cat defends its sleeping owner's dreams, tapping to merge fish into stronger fish-missile ammo.

Clicker Heroes - Idle SlayerUpdated
Also idle, combat
Tap to fight waves of monsters and recruit a team of heroes with their own abilities, in the mobile version of a long-running idle RPG.

Combo Clash - Era WarsUpdated
Also merge, combat
Merge weapon blocks on a grid to power a hero against waves of enemies, advancing through eras from cavemen to future soldiers.

Demigod Idle: Rise of a legendDormant
Also idle, combat
Play a demigod stripped of angelic and demonic power, regaining it through fast idle growth and flashy 2.5D battles.

Dessert Factory IdleUpdated
Also idle, merge
Bake treats in a dessert factory and combine matching machines to upgrade them into ones that make fancier sweets.

Dungeon Crusher: AFK HeroesUpdated
Also idle, combat
Collect heroes who clear dungeons without you, then log in to claim loot and assemble squads for PvP and PvE rankings.
75% idle
Endless Frontier - RPGUpdated
Also idle, combat
Lead a squad of knights and mages up thousands of stages against titans and dragons, with units that keep climbing and leveling on their own while you are away.
75% idle
Epic Stickman: RPG Idle WarUpdated
Also idle, combat
Guide a stickman hero through a shadowy realm, picking a class and gaining power in automatic fights even offline.
75% idle
F Class Adventurer: AFK RPGUpdated
Also idle, combat
Level a lowly F-rank adventurer toward S-rank with screen-clearing area skills while experience keeps piling up offline.
75% idle
Forge MasterDormant
Also idle, combat
Forge gear across eras from the Stone Age to the Quantum Age and battle other players on a leaderboard.

Fortress Saga: Idle AFK RPGUpdated
Also idle, combat
Collect heroes, clear dungeons, and upgrade a fortress in a fantasy idle RPG where your party keeps fighting and gathering rewards while you are offline.
75% idle
Gear clickerDormant
Also idle, merge
Buy, merge and place gears to build a factory, working through levels with their own challenges.

Ghost Invasion: Idle HunterUpdated
Also idle, combat
Capture invading spirits as a ghost hunter, upgrading your trapper's power, speed, and capture radius to take on bosses across new areas.