Echoes+ is a free to play intense retro arcade space shooter game developed by Binary Zoo and published by The Game Creators Ltd.
"Echoes+ is an intense retro action space shooter where players must fight their way through wave after wave of neon coloured space enemies, leveling up their score multiplier and shields as they go. The onslaught just keeps on building with new challenges the further they progress.
The game features six different game modes; Echoes, time attack, survivor, meteor storm, asteroid belt and classic. With four difficulty settings and 100 trials there’s a lot of depth for players to explore. The game also features local and global leader boards."
Mac OS X 10.7 Lion or newer
Intel Core 2 Duo processor or faster
512 MB RAM
OpenGL 2.0 compliant graphic card
23 MB free hard disk space
Free download at steampowered.com