Here's my problem. My playtime is limited to about half-an-hour per session and about two hours total per day with no set schedule. At the end of the day, I'd like to feel to have accomplished something significant that is also part of a long term progression.

The only video games where I've seen this level of pacing are in single player games, but those don't really have a persistent long term element to them. Can anyone think of something otherwise?