It's an interesting premise and the game was pretty cozy and relaxing, but I feel like there need to be more upgrades because once I got 1 - 2 beacon active, I can buy off a bunch of the build upgrade right of the bat, making most of the grind trivial at that point as I can just jump from place to place, and once 4 - 5+ beacon is unlocked, I pretty much don't need to care too much about any of the upgrades (build or otherwise) and can just max out all their upgrade with just 1 click using the "max" buying option.
Not that buying and maximizing upgrade is bad, it certainly give of a "I'm so rich now, Woo!" feel which is pretty nice, but it also make the rest of the game feel empty, especially since the study and upgrade are so limited in their options. It still a fun game to play, but the upgrade does feels meaningless a bit too soon in my opinion.
Edit: Oh yeah, I forgot about lantern glass as well. goes to show just how irrelevant most of the upgrade turned out to be at the end since I forgot to use the glass 90% of the time XD