The clock uses the SMB1 ROM for game logic and most graphics. Changing the SMB1 ROM with a ROM Hack that changes these graphics will also influence the clock.
Run make to dump the SMB1 ROM to build/smb1.nes. Most ROM hacks are provided as an IPS patch file and need to be applied to the ROM via a ROM patcher.
Pass in the path to your patched SMB1 ROM file using the --smb1 argument.
NOTE: No ROM's or romhack patches will be hosted in this repo.
Run make to dump the clock tileset to build/tileset.png. You can copy and edit this file using any image editing tool. To use your modified tileset, pass in the path via the --clock-tileset argument.