This is the hardest Gym game of the bunch. You need to hold a platform steady while blocks of different shapes fall from the sky. As the blocks start piling up, they will start changing color with the red variety being worth the most points. Once you have a nice stack of blocks you dump them to the left or right depending on what side is open. The secret to obtaining the high score for this event is greed. You want to hold out and not dump anything until you have some red blocks on your platform. It is possible to break the score with just 3 good stacks and some quality red blocks. Also there are no "fire" blocks to worry about if you play on Easy.
The other option is to complete Easy mode to unlock Medium mode. Once in medium mode, hold the platform as low as possible so the blocks drop down faster. Some blocks come down on fire and you must raise your leg (left if block falls on left and vice versa) to put the fire out. Get as many blocks stacked as possble, they change color the higher they go. Try and get them to red and then dump them into the traps on the side (when they are open of course).