An excellent anime in terms of character development and story structure.
Don't let the first few episodes fool you. After Episode 12, Steins;Gate begins to explore difficult themes. How many times can you fail without breaking? Are we controlled by fate, or do we have free will? It's intricately plotted like any time travel show, but not overly convoluted.
One of my favourite parts of this anime was the beautiful characterization and development of Okabe. When we first see him, he's shown as a stereotypical chuunibyou and purely delusional guy. However, as he goes through hell and back, you start to see the facade cracking. In no way are you supposed to think he's an incredibly intelligent and know-it-all guy. He's deeply flawed and realistic.
The character interactions are sweet and simply add to the charm of the show. I had problems with the explanation of Luka's gender identity/sexuality (thankfully it's elaborated on more in the VN), but that was about it.
Okay, if you've reached the end of this review and you haven't watched it, go do so! What's not to lose?