Zerath the game has 3 levels of play: Easy, Medium and Hard, corresponding to the monster's stats that also increase. Each level will have the player's character fighting a total of 4 monsters, each monster will appear in turn with HP, Damage and Defense stats increasing gradually, the last monster is the Boss. Each monster has the probability of appearing special bullets such as stun, x2 damage, healing, with the Boss having the ability to shoot all 3 types of bullets, and the ability to be invisible (while the monster is invisible, it will not take damage). In the level, below will appear a grid of items, including: Damage increasing core (purple), Defense increasing core (blue), HP increasing core (green), Bullet speed increasing core (yellow), when you combine 3 similar cores, it will increase the corresponding attribute for the character in the battle, the more cores are combined, the more the index is added. In addition, your character has a special skill called Rapid Fire (shoot 5 bullets continuously) or Immune Shield (immune to all damage and negative effects, lasts for 3 seconds) that will support you. You can use Core (an item dropped after defeating a monster) to upgrade Special Skills (the upgrade interface will appear when you click on the "Special Skill" panel). The higher the level, the lower the success rate of the upgrade. When upgrading, the cooldown time of that skill will decrease. When you kill the final Boss, you will be the winner. When you win, you will receive diamonds and Core. Diamonds are used to permanently upgrade the character's HP, Damage, and Defense by upgrading in the Shop interface. The player loses when the character runs out of blood. In addition, there is a feature to rank battles based on the number of monsters killed and the time it takes to successfully pass the level.