Codename: Eagle is a refreshing FPS (first-person shooter) game for Windows, developed by Refraction Games (from Sweden) and published by Take-Two Interactive in 1999. It can't be defined simply as some specific type of game, because no other game before it had such novel and interesting gameplay and great freedom.

I have searched any games that are similar to Project I.G.I., but the games recommended by so many netizens are almost always the same ones, such as: Medal of Honor series, Delta Force series, Tom Clancy's Splinter Cell series, Metal Gear Solid series, GoldenEye 007 series, Tom Clancy's Rainbow Six, Line of Sight: Vietnam, Thief series, Desert Combat series, Battlefield series, Operation Flashpoint, Hitman series, Crysis, Far Cry, Tom Clancy's Ghost Recon series, and more. But finally I found a game that is much closer (can be regarded as a remake) to I.G.I. series - Beyond Enemy Lines.

Every senior game players should remember the classic DOS game in those days - Wolfenstein 3D (released in 1992), which is probably the first FPS game you came into contact with (the ancestor of all FPS games that came out even earlier than DOOM, for example: Quake series, Unreal series). I do believe that a number of players just started to like FPS games affected by this game.

Project I.G.I. (AKA: Sneaked, IGI is short for Institute for Geotactical Intelligence) is a series of tactical first-person shooter (FPS) PC game with realism elements and excellent graphics & sound effects design. In particular, the whole game comes with fantastic sandbox maps and playing methods, there are even dedicated servers built by fan players for online play. That's why it's so popular that it got numerous positive reviews from players around the world the time it came out (it has been 18 years as of this post, but AppNee is still willing to give it good praise).

On the face of CastleMiner Z, I guess most players are likely to think it as a MOD of MineCraft. In fact, they just look alike. CastleMiner Z is an action-adventure game with very high playability. It was developed by DigitalDNA Games, based on sandbox gameplay, and belongs to the survival type of zombie horror game.