This is 8-Bit Buckaroo, a bytebeat synthesizer programmed in Cmajor. It is a port of an Android app.
You can use the provided synthesizer patch in your DAW or with a handful of tools provided by Sound Stacks. Alternatively, you can use the synthesizer in your own Cmajor patch and modify it.
To use 8-Bit Buckaroo, you need to run the Cmajor patch eightbb.cmajorpatch. This can be done in a DAW or other audio plug-in host by loading the patch inside of Sound Stacks' patch-hosting plug-in. You can also run patches in VSCode with the Cmajor VSCode extension, or use one of the other methods provided by Sound Stacks.
Note that the sampling rate at which the patch is run will affect the results.
Bytebeat synthesis typically involves incrementing some counter variable and generating audio samples by performing compound one-liner arithmetic and bit-wise operations on it. See more at http://canonical.org/~kragen/bytebeat/ For 8-Bit Buckaroo the operations were arbitrarily chosen, influenced by prior art and sonic results.