Downloading a "free full version" of (or any paid game) from unofficial sites is generally unsafe and illegal . Most links using that exact phrasing are designed to lure users into downloading malware, adware, or participating in phishing scams. The Risks of "Free Full Version" Downloads
: These files often contain "cracks" or "keygens" that serve as backdoors for ransomware or spyware.
Since Train Fever is an older title (released in 2014), the developers have released significantly improved sequels. If you enjoy transport simulations, you might find more value in:
: Often includes a Steam key while supporting various charities. Better Alternatives
If you are looking for the legitimate game, it is widely available on trusted platforms. It frequently goes on sale for a few dollars:
: Pirated versions frequently lack the latest patches, leading to crashes, broken save files, and poor performance.