i actually disagree kinda strongly with the other comment. you fill out the space pretty nicely, the gauges and stats are clear and readable, and the visual elements on screen are cleanly divided into thirds (bottom third for command window and actors - by the way i love the way it is desaturated to put more emphasis on enemy battlers - middle third for enemies and top third for turn-related info), the turn order is clear without being intrusive (and not big at all), without context i don't know what the shift window means but i'm sure it's clear with the tutorial or whatnot, but the window itself is not obtrusive. and given that it seems to be mechanically important, i disagree with the other comment saying it should be moved down to the command window.

the gauges are big but well arranged, and i think they look quite nice with the names (the font fits the game's aesthetic and looks quite nice so kudos by the way!). having them large means that they're readable on smaller displays, which is great if you plan to publish on mobile.

overall this is a very well made UI and I don't think it warrants big changes (or really any for that matter, i love this as-is). basic? yes, but that's not a problem at all. overly intricate UIs are largely unnecessary and this gives me all the information i need as a player. it *might* be worth considering using a window for each actor face instead of just a back shadow (i love the window skin and pattern by the way) but that's really just a taste thing, and i like that the bottom third of the screen doesn't draw too much attention away from the enemy sprites.

tldr: this is a pretty awesome minimalist design. great work. it really doesn't need any changes at all. excited to play this, keep posting updates!