As of the time of this review, I recommend against playing the demo; you should instead try the full game out and refund it if it's not your thing. The demo is a much older version of the game with lacking features and various bugs. Saves do not carry over from the demo.

Otherwise, this is a solid action rpg with impactful abilities and a slow-to-start progression. I recommend giving it a go.

This game is extremely grindy. And this is both a good and bad thing.
Good thing is you grind to improve your town, unlock resources, unlock more upgrades, unlock more classes, get stronger, keep pushing. It gives you a sense of progression as you go, and if you like diablo-like gameplay, this game is a gem.
Bad thing is they try to make it as grindy as possible. You lose some % of collected resources when you die. And they make sure you will die. Because you can only improve your character back in town. Even if you found some good gear during your run, you wouldn't have enough stats to put them on. So you will go to a map and suddenly get overwhelmed.
Another thing is that you have your typical progression like pay money to increase armor, potion slots, attack power, attack speed, etc. These are per characters, the cost is also quite high so one run might only fund one or two upgrades. And since they are not shared you would have to do the same for each of your characters. The game also encourage you to make more characters because each character will bring passive buffs according to their level.
If you enjoy this kind of gameplay this game is a god send. For me I am actually in the middle, I like a certain degree of grind but this game is a bit too demanding for me.

Finally, it seems this game has some performance issue on steam deck. After around one hour of play, the game will take forever to transition to the next stage or back to town. Need a restart to get things in order.

This game is awesome. I can't wait for some dumb billionaire to hire me to play it for him so he can claim to be good at it. It's been years since a solid grind has been so fun and rewarding.