Croteam was established on 14 June 1993, as a "garage games" company in Zagreb, Croatia, headed up by six friends. The company's founders were Admir Elezović, Davor Hunski, Alen Ladavac, Roman Ribarić, Dean Sekulić, and Davor Tomičić. Their first video game was Football Glory, a football game which was published by Black Legend for the Amiga 500 and Amiga 1200 platforms in 1994, and then for PC in 1995. Sensible Softwarethreatened legal action against Croteam, asserting that Football Glory was a clone of their video game Sensible Soccer. Croteam ceased further development on the title and released it as freeware in 1998. Their second video game, titled Save the Earth, was a children's game based on a Croatian TV series and released for the Amiga 4000. One year later, Croteam finished Five-A-Side Soccer, an indoor soccer version of Football Glory for the Amiga 500 and Amiga 1200. A long hiatus followed, broken by the first title of the Serious Sam series, ' in 2001, followed by ' in 2002. Both Serious Sam games debuted on Microsoft Windows and utilised Croteam's in-house Serious Engine. In 2002, Serious Sam for the Xbox was released, which consisted of both games with the additional number of cinematics, an updated scores system, combos, multikills, auto-aiming and other console specific features. A sequel, Serious Sam 2 for both PC and Xbox was released on 11 October 2005, using Serious Engine 2. In 2007, development began on , a prequel to the original game. In 2010, Croteam released high definition remakes of the original Serious Sam games with upgraded textures and models, enhanced engine, user interface and audio, and additional features. Serious Sam 3: BFE was released for Windows in November 2011, soon followed by macOS and Linux versions. The Xbox 360 version of Serious Sam 3: BFE was released on Xbox Live Arcade in September 2012, and later made its way to PlayStation 3 via PlayStation Network in March 2014. In December 2014, Croteam released the first-person puzzle game The Talos Principle for Microsoft Windows, macOS, and Linux. Co-founder and chief technical officer Ladavac left Croteam to join Google's Munich-based branch in October 2019 and work on the Stadia project.
Serious Engine
For development of Serious Sam: The First Encounter, Croteam developed the Serious Engine, a proprietary game engine, which, while similar to other engines at the time, was designed to render large environments and support a large number of enemies visible at any time. Serious Engine 2 was developed alongside Serious Sam 2, adding in support for a physics engine, refraction, detailed textures, and high dynamic range lighting. Serious Engine 3 was used to support the high-definition remakes of The First Encounter and The Second Encounter for release on Windows and Xbox 360, adding in true high-dynamic lighting support. As Croteam wanted to target more platforms with the release of Serious Sam 3: BFE, Serious Engine 3 was heavily reworked to support seventh-generation consoles, and became Serious Engine 3.5. With the introduction of eighth-generation consoles, Croteam continued to improve the Serious Engine, releasing it as Serious Engine 4, which premiered with The Talos Principle. Serious Engine 4 is also expected to be used for the upcoming Serious Sam 4, with Croteam claiming it can support up to 100,000 enemies on screen at any time. In honour of Serious Sam: The First Encounter 15th anniversary in 2016, Croteam released the source code for the first Serious Engine under an open-source licence.
