I'll start by saying that first few episodes are tragic from technical perspective. Everything happens way too fast, we jump from scene to scene without any proper transition - like in some recap. Add to it this anime being what it is (explained later) and it's no surprise if you want to drop it after one or two episodes. Luckily it gets better after first few world and character introduction episodes.
The story is as cliche as it gets. No, it's even more than that. The protagonist, Touya, isn't just overpowered - it's whole world that's working in his favour. Things just happen at perfect time for him to profit from them or show off his awesomeness and gather his harem. This aspect of anime is mostly visible in early episodes when he needs to build his fame - it's not so problematic later on.
I had really hard time telling if the story is seriously bad or if it is meant to parody isekai titles that fall into OP MC/harem cliches. On one hand it feels like cheap fanfic written by 8th grader. On the other, story doesn't seem to take itself seriously. All the conflicts are resolved quickly and painlessly without Touya even trying. Actually, most of times it ends up being comedic, even when enemies are serious evil guys.
The general lighthearted feel this anime gives is actually pretty nice. I believe it's not meant to be taken seriously. You just enjoy light comedy and this weird limbo between SoL and adventure.
Now, having very light and comedic story works better if you have nice characters. Smartphone doesn't. The cast is as one-dimensional as it gets. After you saw introduction scene of a character you already know everything there is to know about them. Huge waste, considering it's a harem and story isn't too focused, leaving a lot of time to fill with interactions between characters.
Touya himself also deserves mention here. There is this meme about Tatsuya Shiba being a god. I wonder what should we make for Touya Mochizuki then? He is just out of scale. While I love OP protagonists, his lack of personality really makes it hard to like him. He is most basic harem MC with the most OP powers I've seen.
When it comes to art, Smartphone isn't anything special. It's pretty bland and action scenes are just weak. Backgrounds are bad. While characters look pretty good, they also lack details.
Generally speaking "meh".
After everything I wrote above it's hard to admit that, of all the seasonal anime I watched weekly, I waited the most for this one. Call me crazy, but it's ridiculously enjoyable. If I watched all episodes at once it might be different though. I'm pretty sure I'll rewatch it in future, so we will see.
As it is, I'd be hesitant to recommend this anime to anyone. While I liked it a lot, I know it's pretty weak from technical perspective and not everyone would enjoy its light story.
Hopefully this review will help you make choice whether it's worth watching on your own.
