Character Death / Unconscious / Game Over

I get a game over even though only 1 party member died?

That's intended! Solasta II is about the story of a party of four and their adventure from beginning to end - so losing a character permanently means it's game over (unless it's not one of your four main characters).

Note that this happens mostly because there are no resurrection scrolls / spells implemented in the demo. In the final game, you will usually have a few ways to resurrect dead characters so having one death doesn't automatically leave you with a game over. 

I have unconscious characters after a fight and they can't move!

If you still have healing spells or potions, give your downed characters a bit of help to get them back on their feet! If you're completely out, you can also take a short rest (top right of the screen, the icon with the little guy sitting cross-legged) to heal them. Even if you're out of Hit Dice, they will get back to 1 HP so they'll be able to move.

I ran out of spells / powers / HP and I'm a bit stuck...

Make sure you take a long rest to be ready to take on the world! There is a campfire in the Kobold's camp, as long as you have enough food rations you'll be able to take a long rest there, refreshing your HP, spell slots and powers.