idk where my original comment went, it's my first time taking part in one of these. Basically, great game, very reminiscent of those addicting flash games I played as a kid and it made me realize how much I miss those. Great artwork and music, satisfying SFX, really smooth and addicting gameplay. I love how it gets more intense overtime. Only criticism I have is that I wish it was PVP and that I could play it with friends, but considering this was a game made by yourself within a week, this is AMAZING.
Simple and addicting. Smooth and polished. An absolute 10/10!! Good luck with the comp!
PS: I really hope you continue to build on this, idk how big flash games are these days but they should really make a comeback, especially on mobile app stores. If you do, I would love to see the option to choose different characters and different courses, with a variety of obstacles (like a tree log?) as well. Some river course ideas; a course that becomes squiggly, a course with waterfalls, and a course with some type of fish chasing you trying to knock players off their tube, or all of the above.