Growing up, the computer in our house was a ZX Spectrum clone. Thus, Commodore 64 was the competition; it was faster and had more memory, but its colours were uninspiring compared to the Spectrum's chromatic brilliance!
Tube64 is a very simple tech demo of drawing tubes on the Commodore 64. It's a good starting point for Commodore 64 homebrew programming, and it compiles out via a batch file. I translated the Makefile inside the samples directory (which did not work for me out of the box) to a batch file which requires no other things (such as paths, etc.) to be set.
Downloads
Tube64 disk image - download this to run it in an emulator (I recommend VICE, via the "auto-load on mount" feature)
Source code - Tube64 source code package
Dev kit with ready-to-compile source code for Tube64 - get this if you wish to compile the Tube64 executable and disk image yourself, or if you'd like to develop your own games using this as a starting point! Tested in Windows XP.