I too choose the color option. I find it less distracting, and some of the graphics and colors are even enjoyable. I don't think I have ever seen that theme's reward animation. I will give it a look. But how about rewarding us with money??? :-) OK, maybe just like monopoly money or mileage, or something the brain is already wired to appreciate and truly views as a "reward" if the number continues to grow. Having to sit and watch cartoons is more painful for me than pleasurable and somewhat enfantile. Unless they are snippets of the old vintage cartoons I used to see as a kid like Rocky and Bullwinkle, or Fractured Fairy Tales, Yogi Bear, Quick Draw McGraw, Top Cat, or shows from the 1950's. Those I would appreciate and maybe find pleasurable.
Not to take away from the current animations which are well done and somewhat sophisticated, they are just too long. I want to keep going on the exercises, and they seem to break my stride.
And I would shake up the music as well. I'm getting a bit tired of the jazz, and the bass. I will say that the sound quality of the recordings is

very good. I also like the ambient sound interruptions offered at certain points. They seem "clear my audio palette" at intervals so my brain has to refocus.