Certainly worth playing, if you're interested in that genre.
The character graphics are well drawn and pretty nice to look at. In their regular forms, Rex would be my favorite, but with the magical versions, Pari is hard to beat. His (regular) looks and personality kinda reminded me of Kanji from Persona 4.
Although I do have one little issue: the sprite of Rex during the scene where they try to come up with a name looks a bit weird. I don't know much about perspectives, but seeing his whole mouth from the side and not his eyes is a bit uncanny.
The writing is solid slice-of-life/magical girl material. Light, but amusing and at times tense and exciting. Best personified by Roo, a pink, magical kangaroo from another dimension. What more can you ask for?
The small faux-ATB battles in a visual novel are an interesting addition, although there was more than enough time and the right choices were obvious. But then again, you're fighting green slimes, so the battles might get more difficult in later chapters of the complete game?
The first tune of the soundtrack with its weird synthetic sounds reminded me of Earthbound, one of my all-time favorite games. I really liked that piece. The other tracks fit the RPG-inspired elements of the VN pretty well. Although I was a bit confused that no sound played in the main menu.
As a whole, it reminded me a bit of the RPG Maker games that I played in the early 2000s. And by that, I mean the fond memories of fighting slimes in the only games my computer could handle back then, not the "Looks like a RPG Maker game" sneers that are all over the internet now.
Looking forward to the full version!