Use the mouse to move around the map, LMB to boost speed, RMB to brake.
DeathCar.io is one of the best Io games about racing. Choose a car and you should learn how to use it as the primary weapon as soon as possible because you need to kill all of the drivers around you and dominate the top spot. After you take part in the challenge, you also have to fight against multiple enemies throughout the world. So, you'd better defend your vehicle from all of the hits caused by your aggressive rivals. However, you cannot stand still and do nothing during that combat. Indeed, you are forced to attack the target's rear or their two sides. Boosting your speed will help you move faster, especially when you want to catch someone or escape from predators. It can improve the ability to survive and rank up although it will only last for a short time. Before you make a plan, keep an eye on the map. Good luck!