Zion

Zion is an action game that takes place in the year 2500 AD. Earth was suddenly attacked by planet Gilan, in an attempt to conquer all the planets in the solar system. The Earth Defense Force's desperate counterattacks proved powerless against Saturn, an invincible super-large robot created by Gilan. It can't be damaged by any weapons Earth uses so the only way to defeat it is to complete Zion - a cutting-edge combat robot.

The game has 8 stages in total. In the first stage, you need to infiltrate the enemy base, evade enemy surveillance robots, and reclaim the fighter jet that forms the core of Zion. From the second stage onward, you'll pilot that fighter jet, dodging attacks from enemy smaller robots and collecting parts. The combined robot is assembled in stage 8.