Sonic Chrono Adventure mixes Metroid and Castlevania elements with Genesis/Megadrive Sonic physics and gameplay. The update will be released at the next Sonic Amateur Games Expo - SAGExpo 2014 Act 1. It will be held February 23 through March 1st.
Sonic Time Twisted is a fan game by myself Overbound and a group of dedicated Sonic fans that attempts to recreate and expand upon the foundation laid out by the original 5 Sonic Megadrive/Genesis titles.
Sonic Time Twisted has been in development for over 9 years and in addition to a demo seeing release February 23rd at this year's Sonic Amateur Games Expo (SAGExpo) you can expect to see the entire game released around it's 10th anniversary.
While waiting for the game you can watch this demo trailer below.