Let's assume they are HuCard games, converted to run from CD.
Max Hucard size is 8Mbit = 1Mbyte = 1024K.
Each CD sector is 2K, so each game takes up 512 sectors
At 75 sectors per second, that's about 7 sec per game.
Yeah, I don't think there is anything missing
Much more likely is that they had all this space, and decided to throw some freebies in to use some of it. Or maybe the dev system was being shared