It is important to set aside personal preference, and be able to specifically and adequately demonstrate in an objective and quantifiable manner when a game is not fun. Do not be snide, sarcastic or unprofessional in your arguments, and remember to highlight what is fun about a game first. This is what readers want to know, and they will respect what isn’t said more than a caustic and unfair analysis. For example:
Game X is terrific fun to play from start to finish. It is an action packed, third person adventure through the gritty underbelly of the modern crime world as well as a nail-biting sci-fi shooter. The controls may take some getting used to, but once it becomes clear what the designers intended by using the function keys as the primary form of movement, you’ll wish every game used the scheme. While aiming in Game X can be difficult for those who aren’t very good at shooters, the method does a good job of recreating a real-world response to an alien shootout.