It’s a nice mechanic to make you think that after a hard night’s work, you need to sleep every once in a while. Most will carry over if you didn’t complete them but if you did, you’ll actually be prompted by the game to head to sleep. What Sleeping Dogs does is give you a set of missions you can do every time you go to bed. You’ll never get that feeling like you’re at a part that is either boring or too much and gets you distracted or disenchanted with the experience. You’ll find plenty of things to do but you’ll never feel overwhelmed.
It isn’t as big as Grand Theft Auto but it isn’t small, either. “Just the right size” is how I explain Sleeping Dogs to people. For Sleeping Dogs, I got hooked on the story it told, the characters I got introduce to, and the “just the right size” city of Hong Kong. I enjoyed the open-ended nature of Fallout 3 and the new gameplay mechanics introduced in Skyrim. The games I mentioned above hooked me on gameplay. With Sleeping Dogs I got hooked from the moment I started playing and it didn’t let up. Others such as Fallout, the Elder Scrolls games, and Grand Theft Auto: Chinatown Wars kept me hooked but not quite in the same vein as Sleeping Dogs. I’ve played many open world games over the years and most of them cannot contain my attention for more than 10 hours. That should last you anywhere from 10-30 hours. You could sit there for 30+ extra hours and do everything on the side or you can do some of those side missions but focus on the main one primarily. For the most part, open world games have handled that pretty well. Also, the player needs to be able to control how much time they want to invest in such a game. There needs to be a happy medium of content and length.
While it can be a good thing to say that a game has too much to do, for some players that isn’t something they’ll enjoy. The amount of content that those games throw at you can sometimes throw someone off of actually playing them. I am of the thought that the Grand Theft Auto games are too big for their own good.