I like their focus on flexibility. I've tried a few deep RL implementations in the past and run into issues like their DQN or A3C implementation being hardwired

I like their focus on flexibility. I've tried a few deep RL implementations in the past and run into issues like their DQN or A3C implementation being hardwired in a number of ways to working only on ALE, with no way to use it on other problems (eg the CNN dimensions are hardwired).