Hyper-Psychic Geo Garaga

Both of these single-episode OVAs have similar themes, and similar artstyles. The setting is different, but the tone each of these series gives off is pretty similar, with the main conflict focusing on the persecution of an alien race. The characters, while feeling somewhat different, also have similar motivations in each show. 

Both are sci-fi adventure tales that have a similar artstyle. The story in each anime deal with a conflict between a space species and humans. The characters are also pretty similar in both design and their personalities, and there's even a tiny robot buddy in each that is used for comic relief. 

same generes