Scratch

Put this at the end of the background script:

set 
Appear ▼
 to 
Now

Put this at the beginning of the background script:

set 
Appear ▼
 to 
Not Now

Put this in the sprite you want to appear:

when  clicked
wait until 
Appear
 = 
Now
show
set 
Gravity ▼
 to 
0
repeat 
however long you want it to repeat
if 
touching color 
color of ground
set 
Gravity ▼
 to 
0
change y by 
1
set 
Gravity ▼
 to 
the larger this number is, the higher your sprite will jump
else
change 
Gravity ▼
 by 
-1
change y by 
Gravity

Put this in the sprite you want to change costumes:

when  clicked
wait until 
Appear
 = 
Now
switch to costume 
whatever costume you want it to switch to

As for the faster jumping, just decrease the height you want the sprites to jump to.