Robotics;Notes

both animes give you a sort of "ah ha!" feeling at points as you figure out what is going on in the plot. also both of these are based on visual novels made by 5pb and nitroplus. on top of they they both give off a feeling of friends coming together to work on something 

They both have a similar plotline with both hidden conspiracies and sci-fi elements. plus it's the third of a series of sci-fi games created by 5pb/nitro+ which also includes Steins;gate. 

Both are sci-fi anime based off visual novels made by the same companies and are set in the same universe. Both are also very slow-paced in the first half but speed up in the second. The overall stories are very different from one another (one deals with time-travel while the other deals with robots), though the similarities are most obvious in the two lead characters- Akiho and Kaito are essentially a gender-flipped Okabe and Kurisu. Basically, if you liked Robotics;Notes at all, you will definitely like Steins;Gate. 

S;G and R;N are practically identical in structure, which is no surprise as they both originate from the same author. Both anime start particularly slow, before building up to a grand climax. Both anime also have a well developed romance between the main heroine and the protagonist. Lastly, both anime have a scientific theme to them which is given by both being adaptions of the Science Adventure universe. S;G differs with it's scientific theme of time travel, unlike R;N scientific theme of building a giant robot. S;G also is more story driven with a more exciting plot, while R;N performs much better with it's characterisation and character development. read more 

It is set in the same universe, 10 years after Steins;Gate and it has an intriguing plot. There are mild references to Steins;Gate and they really put a smile on your face. The committee of 300 return as the main villain and Nae (Mr Braun's Daughter) makes an appearance as an important character. Overall it is a very entertaining show with lots of twists to keep you hooked. 

Robotic Notes is not really that similar but there made by the same creator.The main characters kind of dull but the supporting cast makes up for it also I think you should watch/play it because characters from steins gate return and just as a steins gate fan its cool to see previous characters come back in the world you just watch hououin kyouma save from ww111 Sorry for this being horrible I didn't know I had to write a essay about why there similar and the differences 

In both series, there is a similar feeling and involves a female protagonist who is interested in technology that are appealing to the world that they reside in. Although their interests are different, the main female protagonist is determined to make their dreams a reality. Both series also takes place at a school setting where there is a club formed for the series' interests. Both series has some science fiction themes as well as comedy, drama, and some emotional moments in later episodes. 

Both have plots that start with the MC in a robot-related club at their school, but then delve into conspiracies and intrigue related to their mechanical hobbies. Robotics;Notes focuses more on Kaito attempting to solve the mysteries surrounding Airi, whereas RideBack focuses more on Rin's internal struggles with her part in the events. 

Both feature a cynical, sarcastic male protagonist who ends up in a club with an energetic girl enthusiastic about sci-fi (Haruhi about aliens, time-travellers and espers and Akiho about robots) and eventually gets swept up in a paranormal conspiracy that threatens the entire world. The characters in general are very similar: Haruhi=Akiho Kyon= Kaito Yuki=Airi Itsuki= Subaru (sort of) Mikuru= Junna In my opinion, "Haruhi Suzumiya" is a lot better. 

Both have a lead character that is part of a unusual and not really well supported and somewhat unpopular club that’s led by a eccentric and egotistical girl and also lots of comedy and a focus on the day to day side as well as much bigger plot that forms as time goes by as well too.  

Both are sci fi stories that were animated by production I.g and also had visual novels from mages 5pb as well too as a side note and both are mystery themed stories that focus around the mysteries of artificial inteligence and those who would use it for evil selfish purposes and also a focus on the friendships between the characters as well too and both even had some of the same voice actors too.  

Both have as main character a lazy boy (Oreki in Hyouka, Kaito in R;N) who is in a school club without wantig to be (Classics club in Hyouka, Robotic Club in R;N) and he does nothing. Also both anime have a VERY active girl (Chitanda in Hyouka, Aki in R;N) who makes all move. During each anime, the boys fight to stay in their actual lifestyle, but this is not the plan of the girls and the world. Although the animes can look very different, I think they're similar in a lot of ways.