Originally Posted by n00b

Yes. In fact, it's already out.
It's one of JJ2's BIGGEST SECRETS(next to the fact that Jazz is Green)
Open up jazz2.exe in a hexeditor, search for the string 1.23 (or 1.24 if you have TSF) and change the '3' (or '4') to '5'
Congrats, you have now unlocked the totally useless 1.25 mode.