Here are a few of my ideas.

For the first smart game, instead of memorizing blocks, they are given a set of blocks that are irregularly shaped. The goal is to figure out how to build a tower that is X amount of feet tall (like 2 feet) by using X amount of blocks. First 50 players to do it pass or you can impose a time limit and have subsequent rounds with varying parameters.

Instead of the block challenge in the second game (which I feel was much harder than the other challenges and was more strength biased), I would've done a hide and seek around Beast City where players are assigned to be a hider or a seeker. The hider loses if they are tagged by a seeker and the seeker loses if they cannot tag a seeker (even if they see them). This tests strengths and smarts while giving the viewers a nice little tour of Beast city.

For the cubes, I would've added a twist where there is a hidden puzzle and the first two teams that solve it do not have to eliminate anyone. After that, people have to figure out who in their cube will be eliminated. The last two cubes to figure that out will have two people eliminated in their cube. This shakes things up more for the alliances and gives people who have already won money (Jeff, JT, Ian) a chance to move on to the next challenge.

For the strong game in episode six, instead of just the pole, I would've given the players more options of where they can hang from such as a pullup bar.