Based on the game play alone, I want to give the Sims 4 a decent review and an enthusiastic recommendation. However, this far into it's release cycle, with several paid content releases already available, the number of technical issues that I've experienced are simply not acceptable, and at this point I would caution prospective buyers against purchasing the game.
I'm tolerant of minor glitches and graphical quirks, but there are currently some widespread bugs that have severe impacts on gameplay, and many people, myself included, are experiencing technical issues that make the game quite literally unplayable. My current save game won't even launch, and in the last month I've had to uninstall the game and re-download it due to technical issues that made the game unplayable. I wish my experience was uncommon, but if you check the Sims forums you'll find out otherwise. If you have a high tolerance for these types of issues, and don't mind looking for workarounds on a daily basis, The Sims 4 is the game for you. If you'd rather just play a game that isn't an exercise in frustration, I'd probably give it a pass for now.
If the developers ever get their act together and solve these technical issues, I would probably add a couple of points to my score. When the game is working it is fun. Currently the bugs are too extreme, and too many people are experiencing them. I can't recommend the Sims 4 in its current state. This is the state as of July 20, 2015. If you're reading this a year from now the situation may have improved. In any case I would recommend due diligence before purchasing. This is a very buggy game.