Retro Vector is one of six minigames to be found in The Arcade.
You're in a ship, similar to the game Asteroids, and it's your job to rescue ten different astronauts in each level. You're able to repair your ship after taking hits, but you're only going to be able to take three until you have to start all over. You can't touch the walls, either, or anything pink (same color as the enemies).
Be mindful of your fuel gauge (replenished by using the green pads) and approach astronauts with caution. Keep abreast of your surroundings and check every nook and cranny for those pesky space explorers. Once you've gotten every single one, you're awarded with a star for completing this particular game. Check the level select information for the number "10" to see if you've found every astronaut.
Retro Vector will be marked "complete" once you have collected 100 of the space explorers.