The game is like Plants vs Zombies. The zombies are coming towards you and your friends and together you must keep them away by using your bows and other features of this map like cannons, turrets, etc.
The game uses two currencies: Points and Gold. The points are earned by killing zombies and the gold is earned by killing zombies very fast one after another(similar to "double kill, triple kill,..., n kill" mechanic in other games).
The map provides an in-game tutorial so any new player can learn the map easily.
The minigame is supposed to be played with 3+ Players. It is mostly recommended to be played with only 3 players.
The version for this map is 1.13.2 and you must be sure that you play it on a Vanilla server, otherwise it will not work properly.
The best way to understand what is this map, other than downloading it, is to watch the youtube video.