This cafe is no longer open, but it does have different themes depending on what the next trend is. You can find the cafe by taking the opposite exit from the Akihabara strip. Not far from that exit you will stumble upon the cafe and find a menu outside filled with dishes to fit the theme. The cafe was incredibly small and cramped to really appropriately film anything; even then, cameras were forbidden and the employees stopped before I could even try taking any good shots. So the following images are what I found from those that were able to take photos.
All images were taken by http://getnews.jp/archives/1532049
We didn't try any of the food, but from my experience of going to themed cafes in Japan, the food is usually overpriced and of average if not lower quality. You mainly just pay for the experience. Though I can say that the Nier cafe was one of the more cooler themed ones and from what I could see, there were some dishes that looked pretty appetizing. They had merchandise from Square Enix to celebrate the 25th anniversary. The merch sold were from classics such as Final Fantasy, Kingdom Hearts, and of course, Nier. Products extended from mugs, plushies, keychains, soundtracks, and a few figures! Sadly there were no Nier figures, but I'll keep my eyes peeled for those when they're released. What they did have that caught my eye was a music book from the concert of Nier for a cheap price (I believe it was $15USD) That's definitely a collectible I highly regret not purchasing.
So tip for those that find cool themed cafes like this that have exclusive merch, don't pass on it because they're great to have, make cool gifts, or you can probably sell it to your friends if they're super into the trend.