Finds 1238: Metal Storm, Monster Lair, Ninja Spirit, Super Soccer, and Mystery Disk System Game!

I went to a convention and actually picked up three games I've been looking for a while. The games are Metal Storm, Ninja Spirit, and Monster Lair. Being able to find them in one stop was actually pretty cool. It was also locally so that's even better as two of the three are imports. The two on the top were just bonuses. I am glad to have these gems into my collection. Ninja Spirit eluded me for the longest time and the same goes to Metal Storm. Monster Lair I could've gotten a while back but backed out. A wonderful array of titles overall! More for the never ending growing collection. 

I picked this up at a convention and well, it just caught my attention because it has no label. What could it be? I really need to get my disk system add-on plugged in again. My guess is that it's one of the golf games but since you could rewrite your games over and over, it could really be anything in it.