Sonic Adventure is an online game at 43g.Com. You can play Sonic Adventure in your browser for free.sonic teleport into mario world accidently.The Mario World is divided into three different world where there are three kinds of monster living there. r The three monster are the flying turtle, the walking Goomba, the hard shell monster. They are waiting there to attack anyone who fall into there territory.r Help sonic explore the mario world and across to the land to find an exit.