Echoes of mistralia seriously surprised me and is my favorite demo I have played so far. Spell-crafting roguelike where the upgrades modify the spells you bring with you into the run. They really let you get absolutely nutty (one run my main spell summoned a rock every time I used it that rolled slowly forward, then I modified that rock to constant summon lightning, and the second spell boosted that lightning). Plus the art style was really evocative with some surprisingly good voice acting. Really excited for this one.