In Epic Defense Clash, you will be given powerful tools of different types to use against your enemies.
Use the W, A, S, and D keys to move your hero. Press J to attack, and H to use a special attack. With the L key, you can switch between close and ranged weapons, like arrows.
On the planet you're on, you'll have to start by killing smaller creatures. Once you've done that, you'll have to move on and kill the boss to move to the next level and get your prizes.
You should use the rewards you get to buy new weapons, better and cooler armor, health packs, and other cool bonuses to get ready for the next fights, which will be even harder.
Have fun and good luck!