https://frenzy-kun.itch.io/sonic-frenzy-adventure

One of the very few completed fangames. More than 20 levels, 3 characters and many extra things. You can even play with your own characters replacing the sprites.

- Check the new power monitors system

- Can you find all the  giant rings in the levels?

- There's a chao egg in every stage. You can use your chao in the chao garden