"Kobo Deluxe is an enhanced version of Akira Higuchi's game XKobo for Un*x systems with X11. Kobo Deluxe adds sound, smoother animation, high resolution support, OpenGL acceleration (optional), an intuitive menu driven user interface, joystick support and other features. Recent versions also add a number of alternative skill levels with slightly modernized gameplay. Kobo Deluxe uses SDL for graphics, sound and input, which makes it possible to build and run the game on pretty much anything."

Features
- Fast paced retro arcade style gameplay
- Smooth, high speed 8-way scrolling
- Very simple controls - the game is about speed and strategy
- 14 different enemies; fighter ships, kamikaze attackers, proxy bombs and more
- 50 maps, each with it's own feel and strategies to figure out
- Maps are built as you enter them - each game is unique!
- Structured audio technology - hi-fi sound in a tiny download
- OpenGL support for extremely fast and smooth animation
- High resolution support up to 2560×1600 - five types of scaling
- Supports any display color depth - dithering for 15 and 16 bpp
- Supports control by keyboard, mouse or joystick
- Runs on pretty much any hardware and operating system
- All code and data is Free/Open Source! (GPLed game logic; LGPLed engine code.)

Submitter note: When playing in windowed mode under any resolution I had problems with the graphics stuttering. In full screen mode it went away.