Skip to content
keyfinder.
Your game. Your choice of store.
Review us onTrustpilot

Mainframe Defenders

ExplorationTactical RPGTraditional RoguelikeRogueliteSandbox87% positive on Steam
Synthetic DomainReleased 25 Feb 2020
15 active offers across 6 stores

All offers (15)

Compare the platform, region and delivery before you buy.

Delivery

Standard Edition 15 offers · EU & Global

  • Mainframe Defenders Steam CD KeyActivation key
    SteamGlobal
    Lowest price€0.82+ payment fee
    View deal
  • Mainframe Defenders (PC) Steam Key- GLOBALActivation key
    SteamGlobal
    €0.86+ service fee
    View deal
  • Mainframe Defenders EN/RU/HU GlobalActivation key
    SteamGlobal
    €0.93+ service fee
    View deal
  • Mainframe Defenders (PC) Gog.com Key GLOBALActivation key
    GOGGlobal
    €1.07+ fee possible
    View deal
  • Mainframe Defenders (PC) Steam Key GLOBALActivation key
    SteamGlobal
    €1.14+ fee possible
    View deal
  • Mainframe Defenders (PC) Steam Key EUROPEActivation key
    SteamEurope
    €1.26+ fee possible
    View deal
  • Mainframe Defenders (Global) (PC / Linux) - Steam - Digital KeyActivation key
    SteamGlobal
    €1.46no Plus, no Protect
    View deal
  • Mainframe Defenders Steam Key: GlobalActivation key
    SteamGlobal
    €1.91
    View deal

Official store Steam · price for Germany

  • Steam store pageDirect purchase
    SteamGermany
    €4.02No fee
    View on Steam

You buy directly from the store. "+ service fee" or "+ payment fee" means the store adds a fee at checkout; you see the final price there before you pay. We may earn a commission when you buy through our links.

Best price over the last 32 days

€6.00€4.00€2.00€0.0011 Oct 202611 Nov 2026
  • Lowest €0.0717 Oct 2026
  • Highest €0.9324 Oct 2026
  • Today €0.82

The cheapest EU or Global key per day across all compared stores; the dashed line is the Steam price.

Mainframe Defenders screenshot 1Mainframe Defenders screenshot 2Mainframe Defenders screenshot 3Mainframe Defenders screenshot 4

Buy Mainframe Defenders key: current price comparison

Where is the Mainframe Defenders key cheapest?

The cheapest Mainframe Defenders key that activates in the EU currently costs €0.82 at Kinguin. Keyfinder compares 15 offers from 6 shops for this price. That is 80% less than the Steam price of €4.02. Prices are refreshed hourly; region, edition and any checkout fees are shown on each offer.

What was the lowest Mainframe Defenders key price in the last 32 days?

€0.07 on 17 Oct 2026, for the standard edition that activates in the EU. The highest daily low in that time was €0.93 on 24 Oct 2026; today the cheapest key costs €0.82.

Which Mainframe Defenders keys activate in the EU?

15 offers are marked EU or Global and activate in Germany and the rest of the EU. Keys for other regions are listed separately. The keys on offer are for Steam and GOG.

What a game key is and how to read an offer

How do I activate the Mainframe Defenders key?

The cheapest key activates on Steam. You redeem it there with the code the shop sends you after you pay.

How to redeem a Steam key

Is it safe to buy a Mainframe Defenders key from Kinguin?

Before you pay, check three things on the offer: the region (EU or Global for Germany), the edition and any fee added at checkout. Keyfinder shows all three on every offer. Our Kinguin check covers who runs the shop, its fees and its regions.

Is Kinguin legit? Read our check

Games like Mainframe Defenders

More games by Synthetic Domain and games in similar genres.

About Mainframe Defenders

MAINFRAME DEFENDERS - Turn-based tactics centered around gear and unit customization. It offers simple combat, high replayability, and tons of loot. Items don't just provide stats boost, but also offer distinct mechanics that can be combined into powerful builds.

Developer
Synthetic Domain
Publisher
Synthetic Domain
Release date
25 Feb 2020
Steam
View on Steam