Fun game! It's an interesting crackship that I'd never considered but that makes sense in many ways. The visuals feel more cohesive than most mega-projects and the playtime feels about right for what it is.
I found it a bit hard to judge the concept, because the gameplay is just too easy for the game itself to serve as a proper stress-test for the game design. I'm also not sure if just making the game harder would make it better, because it'd probably just collapse the number of meaningful choices to an even smaller number of optimal choices. I suspect the reason simulator games like Princess Maker and Tokimeki Memorial usually presents the player with several goals they can aim for is that this both keeps all options useful (depending on the goal the player has), and also makes for a more interesting way to up the difficulty, where a player short on resources may be forced to choose between their different goals, which is much more granular than just straight up failing the game. This game could perhaps have had an option to spend time with Yachie, which wouldn't affect the outcome of the race, but increases Yachie's affection for a better ending. This would allow for more interesting gameplay where a player who wants a better ending cannot just go all in on rigging the races.
Still, the game is excellent in every other category and the art and writing alone makes it worth playing.