I just got the game and started adventure mode. I realized I was jumping constantly without pushing any buttons and I couldn't get it to stop.
Please help i really want to play this game!

Are you using keyboard controls? It sounds like one of the keys might be 'stuck'; not physically stuck, but incorrectly registered as being pressed when the game starts up.

Try pressing the various jump keys (Z, C, SPACE by default), or go into OPTIONS->CONTROLS->CUSTOMIZE and choose a new jump button.

Are you using an Alienware keyboard or any other with touch buttons? In my case there's these touch buttons that do things like turning wi-fi on/off, and they actually also trigger a button on the keyboard, which stays "stuck" until you press the actual key once. That might be the cause.
I had no issues with jumping with the last update.