If you have time/interest you could make one with http://www.pentacom.jp/pentacom/bitfontmaker2/ or there are a ton available here http://www.pentacom.jp/pentacom/bitfontmaker2/gallery/ not sure what the "use policy" is on those though.
All jams I followed or participated in so far had fonts as one of the exceptions for the "everything has to be done within the timeframe" section of the rules. It would be ridiculous, especially considering some toolsets or libraries have them built in already and these are allowed to be used as well. So don't worry, just look for one you like and use it (of course following its licensing terms). I don't think anyone here minds. :)