Serious Sam: Tormental was developed by Gungrounds, a Croatian
indie game studio. It was the studio's second game after
Rocking Pilot, which was co-developed and published by Mad Head Games in May 2017. Kristian Macanga and Guy Unger initially developed a game titled
Spitfire or
Spitfire Inferno, which they modelled after
Geometry Wars. They had previously collaborated on a game for the "Indies VS
PewDiePie"
game jam held in November 2014. While exhibiting
Spitfire Inferno at the Reboot InfoGamer conference in Croatia, it was acknowledged by members of
Croteam, who tracked the team's progress across further events—Reboot Develop, the Slovenian Games Conference, and the Central European Games Conference—and eventually invited them to Croteam's
business incubator programme. The Gungrounds team grew over time, adding
programmers Ivan Gabriel Juričić and Goran Tomašić, as well as
artist Ana Marija Lončar, who the team had met at Reboot InfoGamer 2018. Additionally, Croteam's Roman Ribarić, Andrej Smoljan and Damjan Mravunac acted as
producer,
sound effects artist and
composer, respectively. Gungrounds used the
Unity game engine since the team members were already familiar with it and because it supported multiple platforms. As the expanded team was unhappy with
Spitfire Infernos theme, Ribarić suggested that Gungrounds shift the game to the
Serious Sam universe. After choosing Mental's mind as the target setting, the game was renamed
Tormental. It drew further influence from
Nuclear Throne,
The Binding of Isaac,
Enter the Gungeon, and other
Serious Sam games. Croteam's incubator programme was formally announced as
Croteam Incubator in March 2018. At this time, Gungrounds was based in the same
Zagreb office as the five other studios in the programme. A prototype of
Tormental was exhibited at the April 2018 Reboot Develop conference in
Dubrovnik to attract the attention of game designer
Rami Ismail, who, after extensively playing the game, gave his detailed impressions to the developers.
Tormental was due to be launched in
Steam Early Access in August 2018 but was delayed to allow for
quality assurance and the completion of some existing features. A prototype was released as
freeware via
Itch.io in March 2019. The early access version, now renamed
Serious Sam: Tormental, was launched on 2 April 2019 for
Windows, with Croteam Incubator acting as the publisher. This version introduced John Dick as the
voice actor for Sam. The game was initially intended to remain in early access for 6–12 months, depending on player feedback and prospective further features. Upon the initial release, Gungrounds announced a shortened prospective period of 2–3 months, though noting that it could change based on internal milestones. The studio anticipated bringing the game to the
Nintendo Switch,
PlayStation 4, and
Xbox One should the first release be successful. With the "Fortress Update" released on 8 April 2022,
Serious Sam: Tormental was taken out of early access with
Devolver Digital as its publisher. == Reception ==