If you're looking for something challenging that will require some research and practice on your part, but will also take it easy on that left hand, try Flight Simulator X.
You'll need a joystick with a throttle on it (Saitek Av8r is a good cheap stick). Your right hand does the flying and your left hand handles occasional tasks such as landing gear, flaps, spoilers, throttle, etc. Your right hand will switch between the stick and the mouse (for autopilot settings). The game teaches you the basics of flight, taking off, landing, lining up for approach, etc. You will have to learn advanced controls (like how to use the autopilot on a 747-400) through online research (everything is easily available). It's a challenging game with 1000s of hours of replay value. There are dozens of pre-fab missions (resort supply, commercial flights, charter flights, a secret shuttle to Area 51, mail supply runs, tourist sight seeing flights, helicopter rescue missions, etc.) as well as the ability to set up your own flight plan (say, San Francisco to Honolulu Hawaii) and fly your own way with your choice of plane. I've been playing this game since 2007 and I'm not sick of it.
If you're comfortable using the WSAD/shift/C/Space keys, you should check into slow paced first person RPGs like I was saying before. Skyrim, oblivion, fallout, etc. You may find Mass Effect 1/2/3 slow paced enough as well.