My best score for Ping-Pong jump is 502 and I tried a few times before reaching this high score. It is a great game with simple control, though it is hard for me to control the ball movement. Sometimes it moved slow, but when I hit the wall or the obstacles coming down from the top, it suddenly became really fast and it will bounce forth and back very quickly and it is really hard for me to catch it.
The central uncertainty in this game for me is the ping pong ball movement when it hits the either the walls on the side of the screen or the black obstacle walls coming down. What I can do is to try my best preventing my ball from hitting the wall, and the tension comes from the fast bouncing and the helpless feeling that I cannot catch that with my reaction. The challenge that designer throws to players are the black walls coming down from the top. There are two patterns for the black rectangles, and players can pass them through the empty gap between two black walls. There is also an interesting point that when I hit the black walls from the bottom with the ping pong ball, it usually will move with a faster speed and it makes me harder to catch it and bounce it back to the air so that it will not fall off. I feel like that you can change the wall position every time when it comes down rather than fixing it into two patterns. For example, you can use the random function and give a range to the random so that it will not generate numbers that is not on the screen, and you can always leave a blank space for players to pass through their balls. Or you can make the black walls more intelligent by using the X positions of the balls when you generate the black walls and make it long enough that players need to get to either the right-most area or left-most area to find the gap.
The other interesting thing that I encounter is the time where I first played this game and I move my pad really quickly. Then the ping pong ball moves in a crazy speed where I cannot see it clearly in the screen and I only got several points in that few rounds.
A way that the designer can create more interplay is to change the pad that is controlled by the mouse into two pads that can be controlled by the keys on the keyboard, and there are two scores separately for each player to keep trach with. In this way, players can invite their friends to play with them and it will add more fun as things go. The designer can also add more randomly appeared objects or sprites on the screen, and it can add more points or multiply their points if one player hits those objects with his ping pong ball.