Defend your base by smashing waves of zombies with an auto-attacking hammer, collect coins for upgrades, and progress through five increasingly difficult levels.

The goal is to protect your base from incoming zombies by smashing them with a hammer. The hammer attacks automatically, so all you need to do is move it over a zombie until it loses all its health. The game is divided into several waves, each bringing an increasing number of zombies. If you manage to survive them all, you advance to the next level, which features a new base, a different environment, and even more zombies. In total, there are five levels.

You will not get far on your first attempt, so you will need to spend coins dropped by zombies on permanent upgrades. Collecting coins can be a bit annoying because they do not appear immediately after a zombie dies, and you must move your mouse cursor over them to pick them up. Any coins left uncollected before your base is destroyed or before you finish a stage will be lost. Fortunately, the number of coins increases with each level, so reaching the next one helps speed up the upgrading process.

Although upgrading starts at the center, the entire upgrade tree is visible and branches out in several directions. Each upgrade node can only be purchased once, but the same types of upgrades appear multiple times throughout the tree. These include increased damage, a larger hammer stun range, or additional weapons such as sawblades spinning around the base, along with special attacks using fire or lightning. All unlocked special abilities activate at the same time when you press the left mouse button, after which you must wait about half a minute for them to recharge.

The farther you move from the center of the tree, the more expensive the upgrades become, although each one helps you earn slightly more coins. However, upgrades must be purchased in order along the connecting lines, so you cannot skip directly to the most powerful ones. To help you spot available purchases, icons will pulsate whenever you have enough coins to buy them.

And that is essentially the whole game. You grind for coins, buy the next available upgrades, and gradually push toward the final stage. Unlocking everything can take a few hours, and there are achievements for purchasing all upgrades related to a specific perk. Everything generally works well, although a few achievements unlock the moment you start the game, and there are some optimization issues where the game slows down noticeably when too many things are happening on the screen at once.