I am aware the this game is supposed to be "gameplay-light" but I think what the game needs is a sense of achievement or reward for completing a stage or level. Perhaps a timer to track how fast you completed a single level? I also have no idea what the Eternities do, so maybe there needs to be a page for instruction.
The game had a good soundtrack that fits really well, my personal favorite being the Kenican Jungle soundtrack. Seriously, I love the entire soundtrack for this game, great compositions. But maybe some additional graphic for emphasis would help, maybe add some extra colors to a character so they don't look bland. The scene on the plane where you interact with the pilot felt very plain to me.
What I think hits me the most that there was no emphasis on how tragic it was for the world to end. Other than the Eternals picking out candidates for immortalizing, there wasn't much of a plot to go along with. The game started with an intriguing note, had no progression plot-wise and ended with a lack of a proper ending.