Shield Shifter is a homebrew Atari 2600 game developed by John Reder / Tactical Neuronics. It was given a limited cartridge release by Good Deal Games. Shield Shifter was later included on the Atari Flashback series of plug-and-play consoles, starting with the Atari Flashback 5 in 2014, and most recently on the Atari Flashback X Deluxe in 2019.

The player controls a turret at the bottom of the screen, firing up at three shield layers that loop horizontally. The goal is to create an opening in the third layer and hit the insectoid hiding behind it, which continuously fires at the player.