Somewhere up the corridor, an automated war-foundry is still filling a production order from a war nobody remembers. It stamps out hostile hulls and drops them toward the settlement below, not out of malice, just because nobody ever told it to stop. Nobody's coming to shut it down, so that's on you.
ECHO DOCTRINE is an old-school vertical shoot-'em-up with one twist: your wingmen are Echoes, self-flying copies forked from a recording of your own flying. They hold to the same speed, the same weapons, the same rules you live by, because they learned everything from you. They can't outfly you.
You print unmanned frames from salvage and send them up the corridor. You fly one by hand; your Echoes fly the rest, and when one goes down you print it again.
A neon vertical shmup: every wingman is an echo of your own flying.