As brought up in this thread before, NGNL is terrible because the writer is trying to write an intelligent main character but isn't actually a smart person.
So instead of having actually legitimately cunning solutions to the games they just bend the rules or cheat, because the writer can't think of a smart way of solving the problem.
This leads into not actually having much content, not a lot of showing the stages of plans or executing them, so they fill time by throwing in pandering fanservice to distract the reader/watcher in a desperate attempt to keep you engaged enough to keep going. I watched it back when it was first coming out, and dropped it a few episodes in; It's not even mediocre, it's like a 3/10 show at best.
This is not even to mention the previously brought up fact that the original light novel author was caught multiple times tracing art from other series, the whole thing shouts of an untalented hack who is getting undeserved attention.
Short version: Go watch/read Liar Game instead. Though it may not give you the softcore pornography that you want.
The art was pretty nice. Although sometimes it felt like the garish colours were burning my eyes out. Overall, the aesthetic was decent. Unique (although not on the same tier as SHAFT, obviously).
Have you seen Sunday Without God? It has the same garish art style, NGNL isn't even unique.