well...
I played your game (and read your description). I will say, it is generally a benefit to have a game which is less linear and repetitive.
Give the player options.
they can be ones that leave the game in a playable but unwinnable state, or ones which can be completed in multiple orders. generally the former is sometimes preferred, and often easier to make, but with the latter you can do things like force a special alternate path to reach the other option by blocking off the path you came from.
use Sokoban to your advantage to make things more interesting. look at the minimum amount of space to get one box around a corner. look at the minimum amount of space to get past a hallway blocked by two boxes. combine these ideas, understand the basics. sometimes I notice that people like to force you to take the long way around, and while this can be annoying, it can easily be made less annoying, and still be more interesting than a linear path.
reference memes like microban-1 or the three box Sokoban trick, but use your mechanics to add your own spin on it!
and design tip: add a tiny bit of shading around the tunnels and holes. it will make the game feel slightly more fluid.
implementing a few of these things will make your game feel lot better and a lot more interesting.