Your local chapter of ASA (Autism Society of America) is likely to offer some good advice and resources. I'd start by starting where the kid is: if all he does is play computer games, try to find a way to play them with him. Try to get him to tell you about the things he likes (such as a game he plays obsessively)to get him to start thinking of you as something of interest too. Do not let it hurt your feelings to be a "thing" rather than a "person" to him; he can't help it. "People things" are harder for asperger's folks to relate to than real "things". Good luck and keep on trying to make contact on his terms, however limiting those terms may be at first.