WormsArena.io is a battle-arena, slither-style game that features worms instead of snakes. The player's main goal is to grow their worm as large as possible in a variety of random environments by directing it to eat colored pellet food on the ground and larger energy pellets that appear after other worms die from collisions with larger worms or the side walls. Their secondary goal is to unlock and use a wide selection of worm skins by earning enough coins, as dictated by their worm's final body length, and watching enough ad videos.
The player starts by reviewing the skin possibilities. The game provides animated live previews and clear details about how they can unlock new skins. Once they select a skin, they make their first attempt to grow their worm in an arena during timed play. If they do well, their worm survives until the timed play ends. If they do extremely well, their score appears on a leaderboard near the top-right corner of the screen.
In a WormsArena.io arena, the player directs their worm to eat food pellets, stay away from larger worms, and collect energy pellets from worms that die. They use different tactics to protect their worm. For example, they might direct their worm to slither in a circle to force approaching worms to collide into its sides. They might use a dash feature to make the worm speed away from threats.