Well, there's a super easy exploit that makes the game an absolute cakewalk.
There's a part of the academy called the arena where you can essentially save and "sign out" of the game (it's called participating in a secret mission). While signed out you accrue EXP on these missions, and when you log back in you get that EXP. The more time you're away the more EXP you get. Changing the system clock works. You can get a character to level 99 in less than 30 minutes.
Apparently this existed on the PSP but you had to put the console to sleep, whereas all you do on the PS4 is press the home button and change the date before hitting continue (saving at the secret mission dude puts you in the main menu). So so broken.
On the one hand it's actually not that big of a deal because from what I've read your characters aren't that much more powerful when they're levelled up. On the other hand levelling up gets you AP so you can unlock all sorts of moves. I wouldn't begrudge someone wanting to use this, but I'm not going to bother for the time being.
I'm enjoying the game so far, I just did the first tactical mission (where you direct troops to strategic locations and retake towns etc) and I got an S rank for the first time (A for time, A for casualties, A for... something else) which I was super excited about
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