tl;dr, how can I bundle a gratis but closed-source game in an otherwise BSD 2 clause licensed free software project?
I develop a free software project which is licensed under the BSD 2 clause license. As an easter egg, I'd like to include a small game in it. The developer of the game has published it as a binary available free of charge from his website, and there is no license or source provided. I am planning to contact him for permission to redistribute the binary.
Assuming that the developer is happy for me to redistribute the binary, but wants his game to remain closed-source, what would be a good choice of license for him to agree to release it as? Basically something that says "copyright blah blah, redistribution in binary form is allowed" would be great.
Finally, is this compatible with my project being licensed under BSD two-clause license? Does the fact that BSD license allows source redistribution mean that someone getting a hold of the game's source would be allowed to redistribute it, conflicting with the developer's desire for it to remain closed source (in the event someone stole the source or something)? Does it conflict with my project even being BSD licensed for it to include a closed-source binary?