Stronghold Crusader 2 is a Steam exclusive, boxed copies will require the service as well 

Stronghold Crusader 2 will be offered through Steam, and boxed copies of the game will require the digital service, Firefly Studios has announced.

Ahead of the game’s planned release in Spring 2014, marketing manager Nick Tannahill explained the developer's decision.

“As an independent developer our resources are limited. For the majority of the Crusader 2 project we have had two full-time programmers and two artists working on the game. That said we still want Crusader 2 to have all the cool and convenient features players expect from a modern RTS and a true sequel to the original Stronghold Crusader," he said.

"We can handle much of the game just fine on our own, so the game’s skirmish mode, AI, single-player campaigns and other core gameplay systems such as co-op have been tailor made by Firefly. However secondary features like achievements, game invites and gameplay stats will be powered through Steam, where the majority of our players come from.”

Steam features intended for inclusion in the game either at launch or through free post-release updates include: Achievements, voice chat, cloud saves, Workshop support, invites, stats, and trading Cards.

While the game will be made available through Steam, those wishing to acquire a boxed version of Crusader 2 at launch can purchase the physical edition at retail. It will still require Steam to play, obviously.

Stronghold Crusader 2 was successfully crowd funded through Gambitious after it was announced in 2012.