Sonic Adventure Blast is a fan game that aims to capture the feeling of movement in Sonic Adventure and Sonic Adventure 2, while making various changes and additions to make it feel new and unique. There are 22 different levels (plus a boss fight), with a total of 60 different missions to collect A ranks. There are also hidden NPC's hidden throughout the levels to collect. You can unlock different skins to play as by finding these hidden NPC's and getting A ranks. A large amount of levels are from Sonic Adventure and Sonic Adventure 2, but there are also plenty of levels from other games as well. Delfino Plaza and Noki Bay have been made into treasure hunting levels, where Knuckles searches for randomized emerald pieces. In Kingdom Valley, you play as Tails, who can use his fly ability to reach the many cliff ledges and structures in the level. There are four different types of missions - Normal Mode, Ring Attack, Lost Chao, and Hard Mode. Ring Attack has you collect a certain amount of rings, which vary per level. In Lost Chao, you have to search for a chao hidden somewhere in the level. Hard Mode is for treasure hunting levels, and the pieces are not randomized, but you don't have a radar, so look closely!