Open Sonic (OS) is a free remake of the classic Sega game Sonic the Hedgehog with co-op play where you can control up to three other players at once. Open Sonic has a nice user interface, and it runs on Windows only because it uses the Win32 API. Once downloaded, open Sonic runs without having to install anything. There is no installation required, which makes it portable and easy to use.
From the start, you'll be guided through the software. From the opening screen, you can easily access a tutorial to help you understand how everything works. If you're not sure how to play, there are also several tutorials available to walk you through everything. If you're a seasoned player, Open Sonic even provides you with an advanced level tutorial. The program will teach you how to unlock various levels and earn bonus coins.
Like all other games that come with the software, you'll find that Open Sonic has a built in level editor. This is useful if you want to expand the game's capabilities without having to write code. You can add new levels, characters and perform any action you like. You can use your mouse or keyboard to manipulate objects on the screen. You'll also find that your speedometer is included in Open Sonic.