This is probably the best retro-themed 2D sidescrolling science-fiction combat sandbox game you'll ever play.
(If you don't like the 'sandbox' part, install the mod 'Void Wanderers' and voila, there's your game.)

This is probably the best retro-themed 2D sidescrolling science-fiction combat sandbox game you'll ever play. (If you don't like the 'sandbox' part, install the mod 'Void Wanderers' and voila, there's your game.)