As far as gameplay goes, the system itself is great, and I had a lot of fun with it. However, I felt that the enemies did have a little too much HP, but it's not much of a problem, since whaling on enemies is still pretty fun. Equipping different items was pretty roundabout though... perhaps pressing W could open a quick item menu?
The writing as actually really great, and made me laugh quite a few times. At first when I saw the writing style I was afraid it would be kinda cringey, but you actually managed to pull it off well! One small gripe is that the game never actually told me how to use items, so I had to figure it out myself. :P
As for the aesthetics... it's Time Fantasy. What more can I say? ¯\_(ツ)_/¯
The theme interpretation is... pretty average, to be honest. It's by no means bad, but it's basically what everyone's doing :P
Overall, I had a lot of fun with this demo. There were a couple bugs, (such as the boss' hp bar being displayed as "Goo" with 1000 hp before I hit him) so I'm really excited to see the full version :D