To play GP Moto Racing 3, follow these steps:

Choose a game mode: The first thing you'll need to do is choose a game mode. You can choose from career mode, quick race, or time trial.

Select your bike: Once you've chosen your game mode, you'll need to select a bike. You can choose from a variety of motorcycles, each with its own unique handling and performance characteristics.

Customize your bike: You can also customize your bike by choosing different colors and decals. You can even upgrade your bike's performance by purchasing new parts with the money you earn from races.

Race: Once you've chosen your bike and customized it, it's time to race. Use the arrow keys to control your bike, with the up arrow to accelerate, the down arrow to brake, and the left and right arrows to steer. Use the spacebar to activate your bike's nitro boost for a burst of speed.

Finish the race: Your goal is to finish the race in the shortest amount of time possible. Be careful not to crash, as collisions with other riders or obstacles will slow you down and can even knock you out of the race.

Repeat: Keep racing and improving your skills to climb the leaderboards and unlock new bikes and upgrades. With each race, you'll get better and closer to becoming the ultimate GP Moto Racing 3 champion!