Doomsday: There Is a System, so I Can't Pass the Speed Pass, Right?

[Doomsday, speed pass, strong protagonist, decisive killing] The apocalypse is coming, zombies are rampant, and mutant beasts are raging. Fortunately, humans can kill zombies and mutant beasts to gain skills. At the same time, you can increase your skill level through crystals to enhance your strength. But crystals are rare, there may be about 10 in a hundred, and the higher the skill level, the more crystals are needed. Chen Peng traveled to this world and awakened the doomsday survival system. You can gain experience by killing zombies, and experience directly improves your skill level, without the need for crystals at all. When others finally use a skill, he is already full of magical skills. When others finally upgraded their skills to level two, he was already level 40. When others finally reached level 5, they found that all the zombies around them had been killed and the mutated beasts were also trapped. When others set up bases and wanted to become bigger and stronger and dominate, they were told that the end was over. Chen Peng, who owns the system, leads his friends to speed through the doomsday and penetrate the entire world!