Maximum Score

[bblessing]

Out of curiosity, what is the maximum score that one can achieve on any given game? It seems like no matter what I do I cannot break 500, even on games with record times. Moreover, it is difficult to achieve high scores on 4x4 games with high success rates, so it appears that the scoring is based not just on time, but difficulty as well. Would it be possible to divulge the algorithm that is used to determine a given score?