Total size when I play this game is 691 MB, tower defense game with lots of rewards for beginners and pre-registration of the game. My suggestion is to take the SSR hero fren (Fearless Iron Cavalry), who attacks directly into the battlefield.
Upgrade
Here we can upgrade the castle and archers for defense. While there are 2 maximum (tower additional ones that have ± 4 types, attackers, give buffs, summon soldiers, and slow down enemies.) can be deployed, towers are obtained by completing required missions.
My opinion
While playing this game, honestly it was very difficult even though there were lots of prizes, because the chance of summoning this time was more to get supporting heroes. It is very difficult to get the same hero and the most difficult thing is because to increase the Hero's star, you need a star upgrade stone with each class. The next difficulty lies in the Hero's skills which are less effective due to the long active time, one of which is summoning after 20s.
Thanks and see you next game...