Assault Suit Leynos 2

Japan-only sequel to Target Earth, Leynos 2 puts you in the cockpit of a giant mecha robot as you scroll and shoot your way through a series of 7 individual missions tied loosely together by a generic sci-fi plot. The game itself plays as a side-scrolling shooter set in different planets as well as outer space (where you can fly anywhere with your jump-jets). You have a variety of upgradeable weaponry which allow you to shoot anywhere on-screen as well as auto-lock individual enemies, and depending on how well you do on each stage you get a specific rating score that allows you to upgrade and customize your mech.