Downloading Grand Theft Auto V (GTA 5) in a "highly compressed" 500MB file is not possible and is likely a scam or malware. The full game requires between 105GB and 125GB of storage space. Rockstar Games Reality of GTA 5 File Sizes
(If you want, I can outline safe purchase options, disk-saving legit install tips, or steps to check/remove malware from your PC.) Gta 5 Highly Compressed 500mb For Pc Windows 10 Extra
Performance and gameplay
Cracking the Game (Optional)