Instead of looking for "highly compressed" versions, try these legitimate methods to get the game running:
Use the "Render Resolution" setting in the game menu to 70% or 80%. This mimics the effect of a lower-res version without breaking the game. call-of-duty-game-highly-compressed-for-pc-gameboy
Searching for ultra-low file sizes for famous games is one of the most common ways users accidentally download viruses. Instead of looking for "highly compressed" versions, try
/ Game Boy Color / GBA: There were for these systems. Any file claiming to be "COD for Game Boy" is likely a "ROM hack" (a different game with modified graphics) or a fake file. call-of-duty-game-highly-compressed-for-pc-gameboy