So, 10/10 is flawless, no bugs, phenomenal graphics, gameplay, story, combat.
9/10 is almost perfect, with extremely minor flaws, top notch graphics, combat, ganeplay, story...
8/10, is a great game With above average graphics, story, combat, gameplay. But a few bugs, glitches and small things that could be fixed.
I see no problem with this review score. Very few games should warrant a perfect 10/10 score. And 9/10 score should be just as stingy a score to give. An 8 is a great score for this game imo.