What began as a technical demo is now a fully playable title. Tusari 2: The River is a compact yet impressive release for the Commodore 64, developed by Martin Piper. The goal? Shoot the ghosts. Collect the crystals. Try not to blink.
Don’t let its small scale fool you—Tusari 2 brings some big innovations to the table. It’s believed to be the first C64 game to combine vertical and horizontal parallax scrolling with variable speed, all while juggling raster-synced NMI and IRQ interrupts for smooth visuals and sprite handling. In simpler terms: it scrolls like butter, and shoots like lightning.
One of the standout features is a technique Piper calls Sprite Shift-Plexing. Every bullet and smartbomb you see is rendered using a single sprite that shifts horizontally and vertically, allowing for multiple on-screen projectiles without a hitch. It’s clever, it’s efficient, and it pushes the limits of what the C64 can do with its 8-bit sprite architecture.
Even better? The full source code is available for free on GitHub. Piper is known for sharing his work, and this project is no exception. Developers and curious coders can dive into the guts of the engine, learn from it, and even build upon it:
https://github.com/martinpiper/C64Public/tree/master/Tusari2/FLDParalax
Tusari 2 is a free download, but if you enjoy the game or want to support further open C64 development, Piper welcomes donations.
