I like the theme at all, I was even thinking about doing a game like that before, it just motivated me again!
But there are things I didn't like about it:
The font used for text-reading is really really messy so it makes it hard to read and that discouraged me from reading what is on-screen(The font is nice, but for reading common text is a lot).
The graphics are awesome, but I think that controlling the raft a bit frustrating as the time to change its direction takes a lot of your health, with that said, I think that the game item's appear is either too random or they move too fast, as It was very very hard to survive