Mahina will play by herself when I just have no time to play with her. She'll knock over her bucket of toys and usually grabs her favorites (one being bigger than her) and take off running. She'll growl while running, shake it around, throw it on the floor and jump back and forth at it while barking. She even plays with my cat (running back and forth chasing eachother). I think it's hilarious.
I do always try to find at least 10-30minutes to play with her. Since she is a puppy thats all she needs to pass out. Haha. Like right now, I was playing fetch with her in the living room and now she's in her bed fast asleep.