Is meant to be included as a bonus for people who buy the game.
Anyway, it's a bugger I couldn't have got here earlier as the full game was free too, but that has since been corrected.
Arcade Archives is a series of re-releases for PlayStation consoles of older arcade games, as the title implies. This is a theme based around the game Contra, which is normally given out as a bonus for people who bought the re-release on PS4. The full game was free earlier today for some reason, and thus, so was this bonus, but now unfortunately, they have fixed the game being free, the theme too will probably have a cost soon, so get in while you can.
And don't forget the voucher code for 30 extra copies:
UP, UP, DOWN, DOWN, LEFT, RIGHT, LEFT, RIGHT, B, A, START
:P