#4722
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.

#4641
CopperCube (successor of irrEdit) is a free 3D authoring editor, also the most user-friendly 3D game engine. It is developed based on the free and open-source 3D game engine - Irrlicht Engine (SWFZ Engine was rewritten from this engine too), and its essence is a simple, lightweight but powerful interactive 3D scenes designing software with concise and clear user interface, convenient operation, and humanized design. It is mainly used in the production of 3D application, 3D game, 3D website, and 3D animation.

#4562
Mario Builder is long-running game making tool specially designed to let any Mario game fans player easily create and publish their very own Mario games, developed by Ting_Thing. The gameplay of levels pre-created by Mario Builder is similar to those you can see in New Super Mario World 2, New Super Mario Bros. 3, and New Super Mario Bros. U.

#2417
Super Mario Bros. X (short for SMB-X or SMBx) is an excellent fan-made game originally developed by Andrew Sprinks (screen name: Redigit). It blended all the classic elements of Super Mario 1, 2, 3 and World along with many new added practical props, such as Ice Flower, Hammer Suit, Tanooki Suit, Kuribo's shoe, The Billy Gun, Yoshi, and more.