I'm always on the look for games in the style of EarthBound (by the way, is Oddity AKA "Mother 4" ever going to come out?), so when I saw this title I added it to my Steam wishlist. And after having read this review, I will almost certainly buy it, because it sounds quite unique and interesting. Also I'm somewhat of a fan of cute things that hide a darker, disturbing side (and vice versa). Tactical boss battles sound interesting too, provided that they are not exaggerately hard.
The game being about a kid with cancer and featuring a dream world that may or may not reflect reality also reminds me a lot of another game, Rakuen, similarly made by a lone person (Laura Shigihara) and with very similar themes, only featuring a more Asian sensibility given the author's background and the links to the Fukushima tragedy. Though it's mostly exploration and doesn't feature actual battles. Rakuen is a hidden gem too and I ask you to consider it if you want another game that mixes comedy with sadness and a bit of darkness too (but not outright horror).