Port of Joust for the Atari 2600 (which in turn is a port of the arcade version). Reasonably faithful to the Atari 2600 version but adapted for the Pico-8 screen, colours and sprite size, with some added particle effects.
Additional enhancements (available in options):

Zen Mode: Play forever without game over (allows lives to be negative).
Turbo Flap: Pressing and holding X repeatedly flaps (like a turbo button).
Players: Switch between 1 or 2 players.
Co-op Mode: If enabled, players cannot unseat each other (they bounce instead). Pressing O will pass a life to the other player (this can be done at any time).
Eggs Fall: Make eggs obey gravity like they do in other Joust versions (they can also fall into the lava).