Galaga

Galaga is the shooting game every later shooting game measures itself against, and the reason is a single mechanic: the enemy can steal your ship and give it back stronger.

A Boss Galaga can open a tractor beam and capture your fighter, costing you the ship but not the game. Survive to the next wave and you can shoot the captor and rescue the fighter, and it docks alongside your current ship - two guns firing in parallel for the rest of the run, with the enormous hitbox that comes with it. That risk-and-reward trade is what makes the game a strategy rather than a reflex test. Everything else supports it: enemies dive at you in looping attack runs rather than marching down, the bonus Challenging Stages offer a fixed pattern of forty ships worth a perfect-in-a-row jackpot, and the difficulty is paced so that the first three waves teach you everything you need. It was Namco's follow-up to Galaxian and became one of the most ported arcade games ever made.

• ▸Enemy tractor beams that steal your fighter - and let you win it back doubled
• ▸Diving attack runs instead of a descending formation
• ▸Challenging Stages with a 40-ship perfect bonus
• ▸A doubled ship is twice the firepower but a far easier target