Athletic World was released 7/1987 and Stadium Events 9/1987. At the time, Nintendo was facing criticism from parents and old/smelly/jaded/clueless people alike claiming that Nintendo was to blame for making America's youth fat & lazy, due to a lack of exercise from playing. In response to this, Nintendo quickly made a deal with Bandai for the rights to the Family Fun Fitness pad in September 1987 (the same month Stadium Events was released), and with it they were able to re-publish Stadium Events as their own game. All Family Fun Fitness branded products were recalled from store shelves, which Nintendo would re-brand as the "Power Pad". This was great for Nintendo because it meant America's youth could still be consumers of Nintendo products while silencing some of their critics at the same time.
1988 was a formative year.
• Nintendo released the Power Pad, which came bundled with World Class Track Meet. This game is actually just Stadium Events but the title screen was altered to reflect a different name. In the game, you use the Power Pad to race against opponents named Turtle 🐢, Bear 🐻, Horse 🐴, Rabbit 🐰, Bobcat 🐅, and finally Cheetah 🐆, each of them increasingly faster in speed as the one before it. Can you beat them all?
• Nintendo released the Power Set, which is a NES system that came bundled with the Power Pad and the 3-in-1 Super Mario Bros./Duck Hunt/World Class Track Meet game cart.
• Nintendo also released the Action Set, which is a NES system that came bundled with the 2-in-1 Super Mario Bros./Duck Hunt game cart. The Action Set went on to be Nintendo's highest selling console set, with an estimated 40 million units sold, making Super Mario Bros./Duck Hunt the most common game cart for the NES.
• Bandai re-released Athletic World with an updated boxart and re-branded to show it being compatible with the Power Pad.
The games Super Mario Bros. and Duck Hunt were also each released as their own standalone games in 1985.
Since they were pack-ins, the game cartridges WCTM, SMB/DH, and SMB/DH/WCTM never came with an official box. The boxes for those 3 game carts in the pic above are custom made so that they look good with the others.