hi and welcome, yes it definitely is. You may very well be the first to break ground on this particular topic. although it's quite a small niche, don't stop and do report your findings!
I'm cross-posting to/from Reddit (maybe we should consolidate)?
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Okay, here's what I found. This applies to the Nintendo Switch version, but I have strong reason to believe the Android version will be very very similar, but all the offsets "might" be off by about 6 bytes(?). If someone sends me a game.dat from their phone, I could take a closer look as time permits, but for now, I'm sticking with the Nintendo Switch format.
This assumes you can get your savegame to and from your Switch (using tools like JKSV and all that homebrew stuff) and that you accept the possible consequences of doing such things to your console. Anyway...
The Switch save file looks something like this:
[32 bytes of magic] (possibly less on Android)
[32 bytes of checksum / hash] (the hash is computed from the start of the 'actual gamesave data' to the end of the file)
[actual gamesave data]
All numerical values are stored in Little-Endian format. Most values as 16-bit, that is, two bytes long (attack, defense, level, etc). Some are 32-bit (money, exp).
The following are offsets for the basic player stats, starting from the *beginning of the file*:
0x0040 - Current level (max = 100, or 0x64) (16-bit) (I only tested 99)
0x0046 - Maximum level (max=100, or 0x64) (16-bit) (I only tested 99)
0x0048 - Experience Points (32-bit)
0x004C - Money (32-bit) (I only tested 99,999 because I haven't messed with wallets yet)
0x0050 - Base level attack points (16-bit)
0x0052 - Base level defense points (16-bit)
0x0054 - "Luck" value (16-bit) ??
0x0056 - "Brave" value (16-bit) (max = 999)
That's all I've bothered to find so far. I'm probably going to get to the Noise Report stuff later, once I get to that part and it gets boring (I've only played through day 5).
Now then, the checksum / hash... As I've mentioned before, the checksum is a hash of the actual savegame portion of the file (excluding the magic / hash portion). On the Switch, this starts from byte 64. The hash algorithm is SHA256, but the trick is that the resulting digest is *byte-reversed* (beginning to end) *and* all the bits are flipped.
Here's a simple python script (attached) that will fix up the hash section of a modified gamesave file (yeah, there's probably a much shorter way to write this but I'm an embedded systems dude and I don't really "do" python often).
Hopefully this helps someone. I'm currently fairly early on, but I'm running with level 99 and 256 attack/defense/luck/brave and it really helps cut down on the time spent in battles. I like to play these kinds of games for the story, and personally I find the fight sequences rather tedious. Don't judge me