This is really neat! The concept of being a river carving a path into a desert is really strong, and the water has a strong weight and force to it thats really enjoyable. Plus, the movement is surprisingly deep (even in just remembering which way you're going to turn next) and the cactus placement is quite nice, leading to challenging but never impossible situations, and for me to take dangerous routes for a fun bend.
I do just wish there was a little more to it. Sounds would help sell the work your water visuals are already doing, and a scoring system would incentivise me to keep going back. A long shot idea, but one I would love, would be if the camera could pan out and show you the path of the river by the end. But all that to say that I do love what's here already, and all I really want is more excuses to dive back in. Really good job dude.