The design for the "Stalker" was based on the "Landstalker" from Ratchet: Deadlocked, they share similar names and movements as well as both having machine guns and a secondary mortar attack.

During the 2006 Game Developers Conference (GDC) where Sony Computer Entertainment showcased a new demo for Resistance, the game previously known as "I-8". The demo showed the game in a much more complete form than the simple FPS that was shown at E3 2005. The gameplay was shown with new weapons very much like the Ratchet & Clank series, only now with a more realistic slant. The demo also showed off effects such as smoke trails on grenades, tactical troop movements, and enemies that came from the ceilings as the lead character ran down a devastated corridor.