When I first played this game, I thought it was a great looking game but with fairly standard gameplay. After reading the comments about how to loop the timers, then the game really unlocked for me.
I think it's a really great implementation of an automation system. Due to the variety of game systems, the player has a lot of agency in deciding what they want their hourglasses to do. Each hourglass earned is extremely meaningful as that not only takes work off your plate, but opens up further looping possibilities.
Ultimately that is the best thing about your game. Instead of just earning money for the sake of earning money or hitting arbitrary goals, you are feeding that effort into a reward that gives the player a lot of value, and is thus worth grinding for. Well done!