Just finished season 1, it was totally awesome and fun watching. I had watched all the episodes continuously till the end of season 1, so there were moments i felt it's not moving forward at the same pace but after the ending i definitely felt good. It was totally satisfying to watch.
Edit: Ow season 2 was on a whole different level. This season focused more on the exploration of all the lead characters, their strength, weakness and more weaknesses. So the plot development was reasonably slow and also everything about this timeline of future, Mars, anything made no sense. It's like they waste too much time on building up. The last episode was great and ended with a mindblowing cliffhanger.
Edit: Yeah, season 3 is great. All those historical figures living in eternity sounds like utopia. This very idea is funny though. At last the explosion of base on true story is what made it hilariously funny.
Since i watched it to spend my time and have fun and not for absolute logic, it's worth it. To be honest, time travelling itself doesn't make sense.