I guess my only takeaway is that if I want to protect my IP then anyone who has access to the software should be required to sign a terms & agreement that specifically written to prevent this kind of thing, regardless IANAL, but i’m pretty sure this is all legal according to copyright law. The engine and therefore the code is different, the assets are custom and slightly different. If this were a trademark or patent related case then there might be a something else to go on.
Indie dev baffled after acquaintance clones his game, puts it on Steam, and acts like it's no big deal: 'Happens every day homie' (www.pcgamer.com) angielski