Like many arcade games of that era, Phoenix is a top-down outer space-themed fixed shooter similar to Taito’s Space Invaders. The player controls a spaceship that moves horizontally at the bottom of the screen, firing upward. Enemies, typically one of two types of birds, appear on the screen above the player’s ship, shooting at it and periodically diving towards it in an attempt to crash into it. In addition to the missiles, the ship is equipped with a shield that can be used to zap any of the alien creatures that attempt to crash into the spaceship. However, the player cannot move while the shield is active, and must wait for a short period (approximately five seconds) before using it again.
Each level has five separate rounds. The player must successfully complete a round before advancing to the next one.
• Rounds 1 and 2 – The player must destroy a formation of alien birds. While in formation, some of the birds fly down kamikaze style, in an attempt to destroy the player’s spaceship by crashing into it. Hitting a bird flying diagonally awarded a bonus score. The birds are yellow in round 1, pink in round 2. The player’s spaceship is given rapid fire for round 2, where the birds fly somewhat more unpredictably. These rounds are highly reminiscent of Galaxian.
• Rounds 3 and 4 – Flying eggs float on the screen and seconds later hatch, revealing larger alien birds, resembling phoenices, which swoop down at the player’s spaceship. The only way to fully destroy one of these birds is by hitting it in its belly; shooting one of its wings merely destroys that wing, and if both wings are destroyed, they will regenerate. From time to time the birds could also revert to the egg form for a brief period of time. The birds are blue in round 3, pink in round 4.
• Round 5 – The player is pitted against the mothership, which is controlled by an alien-like creature sitting in its center. To successfully complete this round, the player must first fire away at the hull and a conveyor belt-type shield to get a clear shot at the alien. Destroying the alien – only one shot is required – ends the level. The mothership fires missiles at the player, moves slowly down towards him and has the alien birds (from rounds 1 and 2) protecting the ship. Defeating all of the birds will produce a new wave.
The game continues, with the difficulty increasing per level. The main increase in difficulty centered on the increasing speed and unpredictability of the bird and phoenix flights.