Main character The Protagonist: EX-1 is a secret agent with the call sign Angel. Together with her subordinates, she goes on an important mission. They have to cope with an alien threat. However, the plan turned out to be not as thoughtful as it seemed, and its implementation became impossible. The detachment failed and was defeated. The girl came to her senses in an unfamiliar place. As it later turned out, this was an alien station. An unknown person's voice is heard in the headphones. He clearly gives commands that need to be carried out. Having explored the base and found the rest of her crew, the heroine will have to get out and save the Earth from the impending threat.

Much of The Protagonist: EX-1's gameplay involves battling off-planet technologies and strange creatures. You have to fight in close combat, using your own fists. For each blow inflicted, the user will be awarded points. If there are enough of them, the possibility of combining them opens up. This will add additional power to the attack and allow you to use new techniques. The developers also allow separate leveling of selected combos. This will allow the player to build his own strategy. All battles take place step-by-step, based on basic characteristics. On his turn, a player can perform only one action: attack or use acquired skills.