Level is getting insanely high because each mob gave way too much exp / level. But you have to get them (as much as any rpgm maker game) to get further. It's just that, even at lv 2k+, a single monster in a level-wise dungeon gave you 30+ level up per victory.
Just don't take the lv / HP / MP for what they show, monster scale the same way....
Only usefull thing are the skill (from weapons & magic cristal), which lv up with use (meaning more accuracy & damage).
I can share my save from the release day JP version. Hope it work.
The game had some good idea, but not the best in putting them together. Hope it turn out better with the EN version.