It is currently singleplayer vs bots and the scenarios are admittedly limited. However, again, single dev (at the moment). Multiplayer is on the roadmap far in the future and will likely not really be pvp as that introduces challenges for balancing.
For now though, the designer is very free in what it lets you do for the most part and has a lot of options.
If you're on the fence, I would recommend looking up some videos on youtube that showcase the game's capabilities. Make sure to pick a decently recent one (ergo past half year or so).
While it does indeed kind of smell like an ad, keep in mind this is not some triple-A bullshit. It's made by a single dev and has a heavily involved community on reddit and discord where competitions are hosted and suggestions are made. Regardless of tankies reputation, that kind of behaviour is not tolerated in either of those communities. I've been playing it on and off and have over 500 hours into it by now. It is a very niche game, but for those that like tanks and military games in general, it is a real gem.