*** Cons ***
The MC is portrayed as intelligent and noble, but his actions are impulsive, impromptu, and reckless. He repeatedly tries to save obviously suspicious people who always attack him and his friends. He doesn't take obvious precautions in most situations against clear dangers, which leads him to getting betrayed just as expected and his friends paying the price. He nevers cuts his losses early. He never exercises any foresight to avoid trouble with others. The MC is not merely naive and trusting, he is a fool who waits until somebody tries to kill him several times and hurts his friends before he takes any preventative, cautious, or retaliatory actions.
The villains are all quite petty and cheesy (mostly rich/popular/powerful/arrogant men who want to rape girls in the apocalypse).
The women all say self-denigrating lines very often like, "In this dangerous world we weak and useless women need to find strong men to protect us. You should seduce him quickly before another woman takes him even if he hates you and you don't like him."
His system is fairly half-baked and the author purposely avoids explaining it so that the MC can conveniently use it at critical moments to win. I feel the system is being used solely as the MC's plot armor device rather than a part of the story's premise like it should be. All background concerning the origins of the system and zombies is avoided. Zombies are not really explained well.
Characters are one dimensional. All his friends/teammates are just obedient or loyal, and if they are female then they want to take off their clothes for him and be protected.
The plot is very repetitive (the same situations, types of characters, and arcs happen constantly). There is little to no real progress after many chapters.
*** Pros ***
The premise is about fighting against zombies with a system. It was intriguing, but ultimately not delivered well.