>>713232605It's simple, it's a 13 character VN with individual progress locks based on progression on other character's routes and the tower defense robot battle. Despite being a VN, each character's route plays different, as it's not just dialogue but actual character movement and decision making is required. As for the robot fighting, you've got 4 generations of robots over 13 characters (3 of each type except for one with 4) and each individual robot plays different enough that you'll have a favorite of each type. Time only progresses when you let it, meaning you can give everyone orders at the beginning and they'll all take place at the same time, along with enemy movements and attacks. Each character can also only fight so many fights before you either need to let that unit rest or give up your point multiplier chain, which is essential for leveling up the robots quickly so you can go through their skill trees and unlock their best abilities.
There's a lengthy in-game dictionary which requires you to read an entry unlocked after beating the game to see the final ending.