+ Solid world and ambiance building.
+ Incredible well-fleshed, balanced and challenging gameplay.
+ No toxic pvp leading to the usual p2w, game is fully pve and you can play and enjoy it at your pace.
+ One of the best "pity" system in a game with lootboxes.
+ Variety of roles and balance in costs means that around 95% of units are quite good and usable without problems, you don't need multiple copies of the same max rarity units to beat even the most challenging maps.
+ Very stable servers with 24/h uptime.
+ Puzzle and challenge maps.
+ Not extremely grindy and time-consuming.
- No easy mode for casuals, and the game is quite hard.
- Story telling seems kinda off, with some questionable decisions and wording, despite having a great world and background.
- Very little stamina and very high stamina cost maps forces you to pay to play if you want faster progress or just leisurely wait for base resources and events.
- No Live 2D in 2020.
- Relatively low amount of premium currency, although this is offset by having less need to use it.
- Not much to do once you beat all maps except wait for event maps and new challenge maps, pretty much like all single player games to be honest...
All in all it's a very good game, specially in comparison with the competition, extremely recommended for players who want a nice strategy game to play in short bursts of time that will keep them engaged and entertained for some tens of minutes, maybe on a car, or waiting for your turn on a hospital.
It's not recommended for those who want to spend 20 hours a day clicking "auto" and grinding resources for what is ultimately a p2w pvp.