I wouldn’t call one “not a real game”. If you like them, great, play them. I have not been very happy with mobile games, myself, however.
A couple of reasons:
While they don’t have to do so, many mobile games appear to me to be designed to cater to people playing in short spurts. That is, you don’t have to build up a lot of metal state about the game; you can play a bit while waiting in a line or something, put the thing on hold, do something else, come back. A lot of my favorite games don’t work like that.
For a number of genres, using a touchscreen is a serious limitation, because part of the screen is obstructed by fingers. Phones can use external input devices, usually via Bluetooth, and so you can make a game that requires an external input device, but it’s an inconvenience to lug one around with a phone, so smartphone games generally need to be designed to be at least reasonably-able to be played on the touchscreen alone. That places some constraints on the way the game can work.
Touchscreen accuracy is limited compared to a mouse pointer, which again limits a number of genres of games.
Not everyone using a smartphone game can be playing sound while doing so; carrying headphones/earbuds around isn’t something that all players will do. That means that smartphone games generally need to be playable without sound, which is a constraint that PC games generally don’t have.
The major benefit smartphones have is that they’re mobile. A smartphone can generally run for a while, as long as most of that is idling. Playing games in most genres burns through their battery quickly. You can carry USB powerstations, but kind of a pain.
Even in genres – like turn-based ones – that really don’t need much battery consumption, for some reason, game developers – unlike developers of many other application types – often seem to feel the need to have stuff going on while nothing’s happening in the game, burning battery life. I’d like to have the option to minimize battery usage.
I would say that a greater proportion of smartphone games than PC games have in-app purchases and ads, neither of which I like.
Many game genres tend to benefit from a wider field of view. Smartphone screens held normally take up a very small portion of one’s visual field.
I am not particularly enthusiastic about having Google track and profile me. A large portion of the commercial games on Android require that one use Google Play Services and this requires a Google account. I’m not willing to get a Google account. This limits availability of many commercial games. I have no problem with getting a GOG account on the PC, and am at least less concerned about Valve, with Steam, than Google.
I have no idea why, but a higher percentage of mobile games seem to go for a cutesy, simplified vector aesthetic. Maybe it’s because they need to run on screens that may vary a great deal in size; I don’t know, but it’s there. Nothing intrinsically wrong with that style, but I’m not especially enthusiastic about it. The Game Boy had the same “cutesy” tendency back when, relative to larger, fixed consoles, so maybe it’s to deal with small screens.
Most mobile games I’ve played that I’ve liked (e.g. Shattered Pixel Dungeon) are also available on the PC, and I find that it’s more-comfortable to play there.
So for me, at least, the mobile gaming experience hasn’t really been one that I’ve been all that happy with.
I could certainly see games that I think would work well with a smartphone. Choice of Games-type multiple-choice interactive fiction, or gamebooks. Those are (or at least can be) light on a battery, are fine on a touchscreen. I’ve generally played those on a tablet rather than a phone – I think that even with those, more screen space is desirable, given the option – but I have done those, and I think that they’re all right. Annoyingly-enough, Twine games – which I would think could be a good match for mobile – aren’t, because Android browsers don’t have an ability to view file:// URLs and Twine builds pages that don’t always work well on small mobile screens. There hasn’t been the kind of explosion of freely-available games in this genre that there have been for the keyboard-oriented Z-Machine and TADS interactive fiction VMs on the PC, though.
Deckbuilding games – though I’d rather have ones without animation or 3D stuff going on, to reduce battery consumption – would be another possibility that I’d like. If cards are designed for a small screen, I think that it’d be reasonable.