I really liked the fact that time was binded to swapping different character, but I found myself having to sit and do nothing for way too many seconds in order to go back to the cavemen. I really liked the art style, but the gameplay was quite lacking in general, the movements and controls were not the best. Also, I managed to go throught the whole game without the need to reach the third character.
The concept is interesting, but I think that you should make swapping between different characters more relevant than it currently is. Hope you will improve this with time, good job!