You dont have control over your unit placement like how they should not going in horizontal system, they should have formation list like square, triangle, cross etc to ensure they are not being close to each other when deployed.
Our characters are really having seizure when defeating all enemies while moving to next section where they will standing still and wasted 3 seconds like an idiot (even more when they used skill on that delay), not trying to move forward ASAP. At least, PAUSE THE TIMER when they moving to next section because it wasted so many precious time when it matter.
When you dont have required unit to battle especially on specific boss, you are being beaten to pulp when bosses have certain skill or extremely tanky on unfavored terrain, it was almost impossible to beat them before time runs out even on maxed skill level (need limit break especially on special events).
Value: Summon system was the atrocious one when it comes to PITY SYSTEM, 200 pulls and you only get pity one when it comes to special units (season event only) while non-special units (including new one) will spawn between 50-100 pulls average even if you are lucky, you will get 2 or 3 at once with cost of another hundred summons again.
Played for 1 year and my motivation was at low point, barely any activities like doing it 15 mins and close the app while waiting cafe and daily stamina filled again. Rewards are extremely stingy and maintenance only give you FIXED 720 Crystals for 6-8 hours maintenance which is really low for such long maintenance (1200 is fine) and events barely give you any crystals at all. Stocking 20k crystals (2 months worth including events) and gone instantly on Limited-time characters with nothing to get at all.