Thank you for telling me!
Lowering the difficulty doesn't lower the amount of EXP gained. I do plan on improving the overall balance, as well as adding more difficulty options in the next big update!
Balance has actually been a tough subject, given I've had report of both people struggling on the easiest difficulty, and other breezing through the default difficulty. At the very least, I do think the game should be easier this early on, so that's the direction I'll be going in for the next update.
That being said, it is possible to complete the demo even by avoiding most encounters! Don't hesitate to experiment with the battle systems. Combos are especially important as they'll trigger your equipped combo spells (which you can stock for later by middle clicking them), increase damage dealt to the enemy when destroying Shapes, and cause energized oyons to appear / purify cursed oyons. Equipping the right spells on the right characters depending on the area, as well as good trinkets and relics, is also very important! Don't hesitate to swap characters mid fight as well as this gives you a slight heal on top of a different spell loadout ^^
Thank you again!