"Highly compressed" doesn't mean "low quality." Modern compression algorithms can shrink files without touching the actual gameplay code. However, you should be aware of:
Downloading "highly compressed" versions of games like UFC Undisputed 2010 ufc undisputed 2010 highly compressed
Below is a detailed look at what "highly compressed" means for this specific title and how it affects the gameplay experience. What is a "Highly Compressed" Game? "Highly compressed" doesn't mean "low quality