Single sim challenges?

I am currently doing the Room Challenge, and its going pretty nicely. The biggest hurdle is social, but my sim worked on his few plants, and got to level 4 gardening. He's now constantly happy and not lonely anymore. I think this is the most interesting challenge I've done so far. Its actually quite refreshing not having random sims wanting to talk to mine.

I use the trespassing option on the front door, and only the mailman has shown up so far :D