It's relaxing (good choice of music), I like that kind of game. I'm not sure to understand the grass to tombstone mechanic, but I went to 50.
Hey, thanks for playing the game and leaving a comment, really appreciate it!
You can press the interact button when around the tombstone to open the upgrade screen and advance the game, hope you'll give it a try!
(I had an interaction highlight in there in a previous version but my testers said it was unnecessary, so I removed it. Probably shouldn't have done that ^^)