https://myanimelist.net/anime/329/Planetes
You're an AI clearing out debris from a space corridor between two stations. The final mission, given as an option on day 6, is to deliver a human heart that can only survive for 1 minute. You traverse by spawning a black hole a meter in front of your ship that's locked in space and exists as long as you're holding down spacebar. You can grab trash on the way to deliver to the far station. you get larger as you pick up more stuff obviously. You can attach little thrusters from your inventory onto larger trash to spend it away. You're locked into your corridor with space buoys that you can also attach thrusters to. You die very quickly if you go past the buoys. You can place down structures to share with your other bonded players. Structures include thruster restock station, repulsar?, map station, explosive station? Very large obstacles need to be chipped away at by multiple players.