Yes, it's fed the score as the reward value used. If I'm not wrong, they didn't normalise it across games for the initial paper but normalised it to some range for some of the following research experiments.
[1] https://www.cs.toronto.edu/~vmnih/docs/dqn.pdf
[2] http://home.uchicago.edu/~arij/journalclub/papers/2015_Mnih_...