Atom: The Beginning

Both are prequels to old school series which also have the same creator. One is light-hearted and fun while the other is dark and gritty. 

Both series focus on a group of friends in a laboratory, while one is focused on robotics and the other is focused on time travel, both series have similar types of eccentric characters... The mad scientist who's actually more of a goofball, his friend who is even more of a goofball, the quiet girl who hangs around the lab, etc. Steins;Gate's story ends up getting darker at a certain point, while Atom's remains generally lighthearted, but the similarities in terms of characters, presentation, and setting are fairly similar. 

Both series tells the story about a group of college student joining the robot club. They told the hardship and the teamwork to complete a robot which rejected by other people. If you like atom the beginning you can try robomaster but i warn you to not have a high expectation of it.