Once the game is compiled and run, you use WASD to move the character. J attacks with a punch and K attacks with a kick. The goal is to defeat all the enemies on the screen. Certain special moves can be performed by inputting certain directional inputs followed by punch or kick. For example, left-right then punch or kick (or right-left to do it the other directions). Rolling from down (S) to down and right (S and D) to right (D) and hitting punch or kick does another move. This can also be done in the other direction. Hitting punch and kick at the same time does a stronger attack.
Enemies will move towards you and attack. Defeat them to increase your score. Some enemies are smaller and faster, while others are bigger and stronger. Two other types take vastly reduced damage weak or strong attacks, respectively.
One boss type is only vulnerable when it is attacking you. Another will remain invisible until it attacks.
You can pickup certain weapons by touching them. They will increase your damage. Medkits will restore your health while purple "poison" medkits will reduce it. The powerup item will restore your health and temporarily increase your damage.
Several interactable elements will appear. Wooden crates can be broken for a medkit. Darker crates are indestructuble. Cars and trash cans can block you. Explosive barrels can damage you if you attack them.
The HUD at the top is shows you your health and the number of enemies remaining, as well as your score.
Your score is checked against the saved high score and is saved if it is greater than the high score.
Code base taken from https://github.com/engineerOfLies/gameframework2d