After getting 32 treasures, Mr. Submarine Commander learns of one big huge giant treasure box! So off he goes in his trusty red submarine (forget all that stuff about everyone living in a yellow one!) in search of the big huge giant megatreasure! But he’ll have to watch out for the usual deadly coral walls, along with a new mean octopus that’s chasing him!

Changes:

Added password system.
Changed wave look.
Added level 9.
now in 3D! Change between foreground and background using the A button.

http://www.atariage.com/forums/topic/166120-gosub-2-virtual-boy/