My 3.5 year old loves to play, but hates to play alone. Left to his own devices he would alternate between "Mom, play a game with me," "Can I watch a TV show?" and running around the house screeching. I'm not sure at what age highly social kids start to play alone sometimes, voluntarily, for more than 2 minutes, but I'm hoping it's soon.

Right now the only time he'll voluntarily play alone is if he's hiding in a corner pooping.
Don't get me wrong, I like playing with him, but I would love to be alone for a couple of minutes sometimes.
When we play lately it's been a lot of tag, bike riding, playground, & races but also Candy Land, Hi Ho Cheerio, play-acting, legos, trains, and marble run.