Can You Play as a Goblin in Shadow of the Colossus (PS3)?

No. Assuming "Sm3" refers to Shadow of the Colossus (often abbreviated SotC), the game features a strictly fixed protagonist: Wander. There are no character selection screens, unlockable playable characters, or cheat codes to play as a "New Goblin" or any other creature.

Why the Confusion?

• "Sm3" ambiguity: Could mean Spider-Man 3 (which features the New Goblin / Harry Osborn as a playable character in some versions).
• Mods: PC version (via PS Now / emulation) has mods that swap models, but not on PS3.
• Misremembered unlock: SotC has no unlockable characters—only time attack rewards (items, not models).

What You Can Do in Shadow of the Colossus

• Play as Wander on his solitary quest to defeat 16 Colossi.
• Unlock Time Attack mode (Hard) for special items: Queen's Sword, Harpoon of Thunder, Cloak of Force, etc.
• Use Photo Mode (PS4 Remake / PS3 Remaster) for cinematic shots.

If you meant a different game (e.g., Spider-Man 3, LEGO Marvel, Marvel's Spider-Man), clarify the title and I'll confirm playable characters.