20461 Dioretsa · FredyGames

About the game

20461 Dioretsa is an arcade space shooter for up to four players on one screen. Each pilot has a small ship, a limited supply of ammunition and a field full of drifting rocks. The ships turn, thrust and fire, and everything in the arena has real weight: ships, rocks and shrapnel bounce off one another with simple elastic physics, so a collision is a shove as often as it is a hit. There are four ships to choose from, each with its own hitbox, speed and strength.

The twist is the flashback drive. Press the rewind button and your ship jumps back to where it was two seconds ago, with the ammunition it had back then. It is an escape from a bad collision, a way to refill in the middle of a fight and a great way to confuse a friend who thought you were done for.

Nobody to play with? Press N on the player-select screen and an AI pilot joins; the AI goes after player 1, so a single player can still have a proper fight against one to three computer rivals. The name comes from a damocloid asteroid, 20461 Dioretsa, which orbits the sun backwards. The game was made by burntcustard for js13kGames 2019, in 13 KB, including its own handmade vector letters.

Playing it here

Click Play, then click inside the game so it receives the keyboard. On the select screen, each player picks a ship and presses their fire key to say ready. Player 1 uses the arrow keys, player 2 uses W A S D, and gamepads join by pressing a button. Add AI pilots with N. When everyone is ready, the match starts. Nothing is saved between visits.

Controls

Input	Action
Left / Right arrows	turn (player 1)
Up arrow	thrust
Space	fire
Down arrow	flash back two seconds
W A S D or Z Q S D	turn, thrust and flash back (player 2; S flashes back)
E	fire (player 2)
N	add an AI player (select screen)
Esc, or X for player 2	back
gamepad	stick to turn, A to thrust, right trigger to fire, left trigger to flash back

A few things worth knowing

The flashback is also a refill. Rewind after you have fired off your ammunition and you get the rounds back.

Use the bounce. Ramming a rival into a rock is a perfectly good way to win.

Play it with friends. The game is at its best with several people on one keyboard and controllers, shouting at the screen.

Credits and licence

20461 Dioretsa was created by burntcustard. It includes ZzFX (Frank Force) for sound effects, the Collisions library (Sinova) for hit detection and part of Kontra (Steven Lambert) for the game loop, all under the MIT licence. The game is released under the MIT licence as well, and the licence texts are linked from this page.