Fun concept! It might be a skill issue on my part, but I found it very difficult to do the Subway Surfers and the shooter gameplay at the same time. The only reason I made it to any bosses is that progress doesn't seem to reset when you die, and I'm not sure if that's intentional. It's also a little annoying trying to shoot and dodge bullets that move along all three axes when yours only go forward along three possible lanes.
I don't know if I understand the DAD fight--nothing I did seemed to have any effect at all. I gather that I'm supposed to pet DAD with left-click, but nothing seems to happen when I click. Also, when you die during that fight, you still can't shoot after you respawn.
Despite the problems, though, it's actually still pretty darn fun. The game looks really nice, too, and definitely stands out.