It is 100% impossible to do a story that takes place at a game company without ripping off New Game. Truth.
Not that it was bad even if it had been a rip off. Its only real issue was that it was a bit on the short side, though it did conclude things reasonably well.
As someone else already posted this is only part of the chapter and they listed a link for the full thing. Sounds like the translator was only given these 4 pages and not told there was a full chapter worth of material.
Turns out bartender is secretly the most skilled pilot in the world and is the only human trained in the use of a proof-of-concept advanced military fighter aircraft fitted with experimental weaponry, and Earth's only hope.