It looks like an address line on a ROM is floating, or shorted to VCC.
I can't tell due the the bloom in your picture whether the red lines appear under the sprite, or are added into the sprite. (Depending on how this behaves could point to whether it's a data issue (Bad rom data, bad rom, bad connection from rom, bad trace), or an issue with the MUXing of the data (the logic that handles displaying transparencies in sprites.) If you only see problems with this one game, then it's most likely a data issue.
The fact that the line repeats every 8 pixels (from what it looks like), makes me think that the pins that sends data representing the high bit of the red channel is stuck high.
If you have a multimeter, check for continuity between the top of each pin of every graphics rom (C1-C8), and where it is soldered into the board. If everything has continuity, then check from where each pin is soldered into the board, to where each trace ends up (or the spot where it routes to the other side of the board).