2005 Honda rincon 650 problem!

So I just bought this 2005 rincon and I got to riding it on the first day and it was fine. On the next day I had it out on the road (not the best idea I've had) and it would get up to 40 and it would start redlining, and it would drop down a gear and then back up. Then when I got to the trails I heard some clicking in the back and I started pulling on the axles to see if that had broke and they had some play In them, and when I would wiggle the four wheeler I could see the wheels moving. Any ideas on this? I've always had straight axle atvs so this whole independent rear suspension is new to me. Anything would be great!