Scott Riesterer of Sublime Sound has posted three retro game-sound Reaktor ensembles on his site.
Says Scott:
A while back I stumbled onto Adventure Kid’s single cycle waveform libraries. I really wanted to use his NES waveforms to make a synth that could produce chip tune style sounds reminiscent of those games from my childhood. At first I tried using Kontakt, and it was fine for just simply performing one type of sound at a time, but I wanted to dynamically blend them. I decided I’d have to use Reaktor to make it work. I used the structure of the included “Sound School Analog” synth and replaced the oscillators with samplers that play back the NES waveforms. I also designed the user interface to look a little like an NES controller. If you listen to “Pixelated” below you can hear my Pixelator synth in action.
The download link is on Scott’s site, and you can also get the instruments in the Reaktor user library.