I'm gonna wait for Steam version
Free work is ok if it's not-commercical project, such as modding for game. If it's commercical and they're going to make money off your work then it's unfair.
Team Polymath: Delirium Trailer
A trailer for the Delirium video game developed using Unreal Engine 4. This project was created as pitch to showcase the abilities of the Team Polymath studio. It is set in a world of nightmares with three distinctively looking environments. All of them provide the main character with some unique abilities.
© Polymath Lab, 2015 Vimeo Link