CIG also argues that the "exclusive rights" to CryEngine granted in the license agreement do not extend to a requirement to use that engine. "The plain language of the GLA where the grant of rights to CIG appears, plus the well-established concept of an exclusive license, instead establish that the word 'exclusively' simply means that CIG’s right to use the Engine in the Game is exclusive to CIG and Crytek may not give that right to anyone else," the company writes.
It's clearly CIG being "selective" and "misleading" here, by claiming that "exclusive" use of the engine meant that Crytek would never license it out to any other company, which is an absurd proposition considering CIG even went on to use Amazons licensed version of Cryengine.
I think you misread CIG's position. All of section 2.1 is predicated on "Crytek grants to Licensee a world-wide, license only:". 2.1.2, which has the "exclusively" language, is about only CIG and its subcontractors doing the development work, meaning that they can't open source the development work against the engine (see the reference to 2.6) .
If the intent had really been to require CIG to use Crytek, it should have been in section 2.2 ("Restrictions on use"). It would have been easy to say "shall not license a competing engine or use Crytek via another licensee".
IANAL, but I've negotiated and signed more than a few licensing agreements, and I don't think I've ever seen one where the license rights to use something are considered to be a requirement to actually use it, let alone a prohibition on also using another solution.
And since CIG doesn't seem to be disputing their obligation to pay for the license... what's the remedy? Force them to include Crytek code and just never call it?