Even the trial actually have quite a lot content!
There's [Mission] option in the town menu where you can tackle mission for reward.
There's this very unique mission where it's actually a minigame akin to mouse maze where you must not let your mouse touch the scrolling white border.
Talk with everyone in the [Info] town menu.
-A female mage in second town will trigger a mission where you must have sex with all enemies to clear.
-Some dude in second town will trigger a secondary branch path of the first stage, where you can obtain Earth-Stone-Club-Weapon thingy (which IMO doesn't really that amazing of a reward)
Extra Gameplay Tips:
Space to Guard.
You can set three weapon in your active slots from [Setting Shortcut], swap through them with left and right keys.
A long ranged enemy (In the demo, there just only the usual mage but she stand quite far in the background) cannot be hit with melee weapon, but their ranged attack can be countered the moment it turns red, just like normal counter.