Nice! I love it when the sumos try to jump on you and it shakes the ground!
Yeah - any game is made better by the addition of sumos...
It seems like you are using integer positions for the background textures. If you use floating point positions, the textures will be drawn with sub-pixel smoothing and this will look way better. (Notice the jittering of the background as you move).
The jittering is purely an issue with the video encoding. When actually playing the game (or in high-quality, 60fps video), everything is nice and smooth.
This game is very addictive for me. Those sumo guys crack me up! I really like the way the enemies just crumble to dust when you kill them!
Glad you enjoy the game!