In the not-so-distant future, a fate-bound settlement installs a gatekeeper robot with no limbs or memories.

To guard the settlement in this post-apocalyptic world, the gatekeeper robot must respond to various visitors, from mutants and thieves to even rogue microwaves.

Can the gatekeeper robot truly protect the remaining days of the settlement?

And what is the true identity of the Flat Machine...?

+ Ultra, Ultra, Ultra-Simple Battles
Intense battles with just the right timing taps. Your strength depends on item combinations!

+ Various Events
Suspicious individuals, monsters, bounty hunters... The daily life of the apocalypse brings one event after another.

+ Multiple Endings
Your actions shape the endings. Strive for the true happy ending!

+ And More
This game can be played for free until the end (in-game items for skipping reward ads can be purchased).