I think Langrisser Mobile is a ok game with a decent story, a fine combat system with weapon triangle and cast of characters though i find the summon a little disappointing since you'll be praying RNG for ssr hero's as players like myself who wants to collect all the hero's but once you have that hero you're used to, you pretty much don't need a ssr but i still find it quite disappointing. you can stock up all you're trinity vouchers as i did during my first day, i managed to save up 100 trinity vouchers in just 14 days by doing many quest, daily logins and using trinity crystals to buy 10 trinity vouchers that cost 800 trinity crystals but can be acquired with patience and if you're up for the grind.
The stamina system is quite unessecary in a game that requires grinding from secret realm levels,story mode, time trials and world events that will cost 10 stamina or more. you can save up your stamina recover items and use 30 trinity crystals to recover 100 stamina and do daily missions.