Released around August 2014, version 2.2.5 marked a turning point for Unturned , as developer Nelson Sexton began the massive overhaul that would lead to the modern game. The term "hot" in your search likely refers to trending community-made "hot" patches, hacks, or "antique" installers that keep this decade-old version playable today.
: Look for community-hosted "Antique" downloads or check the Steam "Betas" tab (though 2.2.5 is often replaced by newer legacy versions there). unturned 225 download hot