Video game writing is a fairly new field, and there are no hard and fast rules about how long a video game review should be. Some will argue longer is better, as this gives you a chance to immerse the readers. Others will say that brevity is key since people just want your opinion, not a novel.
Most game journalists agree that a review should be long enough to give the reader a clear sense of what the game is like, without being so long that it becomes tedious to read. In other words, get to the point, but don't linger.
A good rule of thumb is to aim for around 700-1,000 words, although some reviewers go shorter or longer depending on the game and their own writing style. Ultimately, the important thing is to make sure that your review is engaging and provides enough detail to give readers a good idea of whether the game is worth their time.