I know you have been very critical about your own project but I absolutely love the "look and feel" of this game. The ball has a lot of weight and hits hard but perfectly. I very much enjoyed playing this version of golf.
Visually speaking the game is very minimal and a bit bland, but the lighting gives it the flair it really needs. I love how stuff that our out of light range are just invisible by being kept in the dark. The slight static noise seems to be done incredibly well. However this should be tested well for people that get very quickly nauseous by this.
If this wasn't a game jam and you had your full time to develop this. More mechanics would do amazing. And this game could be the next golf with friends.
Speaking of which. I think this game could work wondrously well in multiplayer, especially well in troll multiplayer like "golf with friends". Maybe experiment with 3d to see how the current mechanics would hold up.
I absolutely loved playing this game and I think this game with a bit polish and more mechanics would be great on steam. I really do think this game could turn successfully and make a profit.