Reality Factory

I decided to make an one day project called super mario rampage 3D.At the moment I'm making a very big game called Metal Force,but I decided to take a break and make this little game which may get bigger after I finish Metal Force.OK so I got the 3D model of mario (of course is not the original and actualy it's called Nario,but that's another question ) my problem is that when I impored it to the game Mario didn't jump properly.He only jumped 1 or 2 centimetres from the ground.Can you tell me why is that and how can I fix it.

not many details.
Please provide more information.

I do not recommend Making fan based games withought Express consent

Well it is not actually mario.OK I fixed the problem now I got a question:I wanna make guns come out from the boxes you hit like in the original mario when a mushroom comes out from some boxes