Sonic in Resort Planet is a free browser/application ported onto operating systems like Windows, MAC OS and Linux. Although it is a short game, Sonic has many abilities to beat the game.
Instructions:
Press enter to start, arrow keys to move, Z key to jump, down arrow key + Z key is to spindash, Z key + X key to do homing attack, C key to do ring attack, Z + A to do dropdash, and Z + S to do insta-shield.
Collect the emerald to get invincibility,
get all the rings!!!