Idle Monster Frontier 9+

Collect, combine, conquer‪!‬

Iron Horse Games LLC

    • 4.7 • 813 Ratings
    • Free
    • Offers In-App Purchases



Collect monsters and combine them to become the epic heroes of the frontier in this idle RPG.

Long ago, the Old Gods, heroes of a forgotten era, united their tribes to purge The Darkness from the monster world. Now, The Darkness has returned, and the Old Gods are blind to the threat. It's up to you to collect monsters from every tribe, and combine them to save the world from endless darkness in this idle rpg.

If you're looking for one of the best monster collecting games, or one of the best idle rpg games, look no further.

Build a team of heroes by collecting monsters. There are over 150, and more to see. Merge monsters to double their power to prevail in monster battle.

Unlock monster fusion to merge monsters into legendary heroes. Combine monsters to unlock extra slots for skilling.

Each monster has up to 6 skill slots, depending on their rarity. Epic monsters and Legendary monsters have more skill slots. Skilling is just as important as leveling.

With generous offline progress and offline earnings, your monster heroes never sleep. You can even capture monsters offline! Sit back and watch the idle action game unfold while your legendary heroes clash in this auto RPG. Prestige to the next level when you're ready for more epic monster collecting.

The idle adventure never ends. With incremental mechanics and no damage, distance, or level caps, this endless auto idle rpg game is not your average monster collecting game. Monsters adventure through the frontier and win monster battles to collect monsters and gold to bring back to your base. Discover new areas and strategies.

Adventures always start at your home base. Command your monster team to explore the frontier, then sit back while auto rpg mechanics take control of the monster battles. You can use potions and spells to help your monster team battle.

Level up your home base to unlock potions and spells. New options for skilling and leveling up unlock as you reach new distances and buy buildings. Explore monster fusion in the Secret Lab, and participate in monster sacrifice at the Altar for permanent boosts.

After you prestige, your monster team can enter the Tower to battle legendary heroes and epic monsters. Defeat every monster team in battle to climb the tower. Collect gems and monster rewards for every victory.

What’s New

Version 2.3.0

New weekends: Crack in the Aether and Fused and Furious
New monsters: Lapis Manalis and Maestro Malaperi
New traits: Bide, Bug Zapper, Feast, Harmony, Unity
Add hidden stats page
Add calendar of events to player's guide
Tons of fixes

Ratings and Reviews

4.7 out of 5
813 Ratings

813 Ratings

James_702 ,

Best idle game I’ve experienced

Played a vast majority of idle mobile games and they usually fall into one of 3 categories.
1 Tap heavy, where u sit there mindlessly and tap away your soul for progression. 2 Ad revenue centered, where at every corner your hit by an advertisement stopping you from using the app. Or 3 micro transaction hell, where at first the game will hold your hand and make it seem like your very strong but at some point you hit a progression wall and they attempt to make micro transactions very appealing and almost the solution to continue playing. This game on the other hand is the most balanced and enjoyable idle game I’ve played. All supported by the unique pixel art style that reminds me of Pokémon. The ads are completely option and despite the occasional pop up wanting you to buy a bundle or what not (only happens when your squad dies sometimes) the game is fun and is one of the top tier idle games out there. Would it keep me coming back? Sure for a while but all idle games for me become stale and are eventually uninstalled but I’m happy to support the devs by watching a few ads here and there because it’s obvious this isn’t ran by a giant Corp and the wholesomeness of the game is still intact. Hope it stays that way !

Idnaisociehsgagaoapajba ,

Definitely an idle game, definitely going to play for years

A lot of people in reviews (mainly steam) like to say this game “isn’t an idle experience” first of all I’m a late game player who hardly touches the game while it’s running. So that’s pretty idle. Second besides clicking and scrapping the game has such little human interaction after a certain point you’d be foolish telling me otherwise. Besides that, this game has been beautifully coded, and being a player for less than half the year, I can confidently say this game still receives minor QoL patches (user submitted) here and there despite talking with the dev personally to see that the game itself is considered complete. At this point I’d like to say if you have any interest checking this game out, just do it. You can strive being F2P, and if you join the community discord (that the dev literally sits in sometimes and talks to absolutely everyone) you won’t ever have to worry about a thing. Download this game.

Datvivar ,

Very Addictive - F2P - Great Depth

Hands down, this has been one of the best phone games I have ever played. With the nuances of giving different skills, leveling up monsters, leveling up skills and trying to get rare legendary/master monsters (and creating different teams off of what you get) this game has me hooked. Although a bit grindy as a f2p game, you get good money when you leave the game (and a couple of monsters to) so you don’t have to over commit to just playing this. The rpg elements of this game combined with this ease of play and flexibility for me to live life, well, this is definitely worth a look at (if you don’t already have it installed. Great game.

App Privacy

The developer, Iron Horse Games LLC, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Used to Track You

The following data may be used to track you across apps and websites owned by other companies:

  • Purchases
  • Location
  • Identifiers
  • Usage Data
  • Other Data

Data Linked to You

The following data may be collected and linked to your identity:

  • Purchases
  • Location
  • Identifiers
  • Usage Data
  • Diagnostics
  • Other Data

Data Not Linked to You

The following data may be collected but it is not linked to your identity:

  • User Content
  • Usage Data
  • Diagnostics

Privacy practices may vary, for example, based on the features you use or your age. Learn More


  • Game Center

    Challenge friends and check leaderboards and achievements.

More By This Developer

Tap Tap Dig - Idle Clicker
Idle Monster TD
Swarm Simulator: Evolution
Idle Hero TD
Idle Hero Defense
Idle Zombies: Build & Battle

You Might Also Like

Hero's Quest: Automatic RPG
Dungeon & Alchemist - Idle RPG
Dunidle: 8 Bit Idle RPG Games
Hybrid Warrior
Shadow Knights : Idle RPG
Tower of Hero