I don't remember game ports on any of the Thinkpads (I worked for IBM at the time and serviced a lot of the very early 700's and 710's).
They had parallel ports, DB9 serial, DB15 VGA, and a couple of PCMCIA/PCCARD slots, IIRC.
Game ports were DB15, and as the Thinkpads were squarely targeted at business users, taking up the real estate for a "game" port would seem unlikely, and possibly even a turn off for buyers of that era.
At some point internal modem's and NICs came along, but I think we might have been out of the 90's by the time that happened. I remember juggling an analog modem, 10Mbps Ethernet and 4/16Mbps Token ring PCMCIA card, depending on what I was doing at the moment.
