... Earthworm Jim 3 and MK4.
How do I know ?
If we count all the games made in 1997, only 3 were made under JY. While in 1996, Hummer team made 6 games !
So if he had those 2 games (EWJ3/MK4), we can count 5 games.
And actually it would make sence since KoF96 was more likely made in 1998. So the music guy and Y.Y.C was still working with Hummer Team.
Also, EWJ3 use the DKC4 engine. Also the SMW music being in EWJ3.
And I just saw that EWJ3 and DKC4 easter eggs use the same number of button.