Tennix!

Tennix!, a tennis game developed in C leveraging the Simple DirectMedia Layer, is an excellent game for players that love to relish in a good tennis match. One of the best parts of the game is the flexibility it provides, as Tennix! is playable in two-player game mode and a single-player mode against the computer, giving all types of players the chance to jump right in and enjoy the game. Not only this, Tennix! currently operates on Linux, MacOS X, and Windows, making it a truly accessible game for anyone on these platforms, with other platforms soon to follow, provided they support SDL.

When starting out with Tennix, you are met with a range of gameplay hints. The game advises players to swing the racket as late as possible to hit the ball harder. Furthermore, players must remember that the course of the ball's trajectory is affected by where the ball hits your racket on-court. Lastly, if your opponent is at the bottom of the screen, it's wise to play the ball to the top edge to maximize your chances of winning.

Another great feature of Tennix is that it is distributed under the GNU General Public License, Version 2, enabling users to download and use the source code for free. In conclusion, Tennix! is an excellent choice for any player seeking a good game of virtual tennis, with its accessibility, gameplay, and open-source distribution all contributing to its great reputation.