Ended up getting every diamond and fruit here, the gambling mechanic ended up really fun! Ended up with 9100 points at the end. Felt like I had to carefully plan my moves so as to not screw both myself and my points. Having the controls be simple yet very slippery added a good skill element to the gameplay, while emphasizing block placement.
There did come a point where I felt it was worth it to "Riichi" before every collectable, unless it was literally impossible to collect deathless, but I think that's a good reward for being skilled at the game! Kinda wish there was an option to spend 1000 to clear the screen without spawning the goal if you have less than 1000 points, but that's a pretty minor thing; if you're doing that you've probably already lost.
Cool stuff!