As Donnie feels regret rather than being bitter over it, I would initially assume its just a coincidence, after all it was a fairly well publicised and popular game in its era.
It is a very good film however, although I would say its one you are likely to want to watch a couple of times at least to truly understand it - in some ways it has the same types of issues that films like Pulp Fiction and so on have (even if very different genre), in that a lot of what happens early on passes you by as superfluous but actually is fairly meaningful in the end.
Its hard to discuss the open to interpretation aspect without really getting into the spoilers so I probably wont, but I would say it does a good job examining a couple of very interesting philosophical issues in a way that is compelling and involving. Overall it makes you think, which can never be a bad thing. Certainly one or two of the core topics it revolves around there really have to be left open to interpretation at the end, because if philosophers/scientists for thousands of years havent been able to come down decisively on one side by now, its fairly certain a 1h30 or so piece of entertainment isnt likely to come up with the final answer, but it can raise the question it an interesting way.