Looking for 2 long lost dos game (1 with killer balls)
 

Both have very good graphics.

GAME 1.

Well, I remember playing this game when I was like 8yrs old.

From what I remember this is how the story goes,

An evil big black ball calls upon its minions : A large red ball, a yellow ball and (*I think) a blue ball to eradicate dungeons of captive humans.

You play as one of the 3 colored balls in a 2d side (non scrolling) background, captive humans abound in dungeons (with electric doors). You have to roll the ball on the switches to open em and then roll down the slopes crushing the unfortunate runaway captives.

Basically its a 2d maze puzzler like game. There are switches for fans and the like, to get to high places.

GAME 2

2d underwater side scroller, you play a submarine that (in the shareware version) ultimately saves a trapped Beluga whale. Lot of ecology lessons to be learnt here.

Any help will be greatly appreciated!

#2 ?? http://www.mobygames.com/game/dos/undersea-adventure

Nope, that's not it. #2 was a sidescroller action adventure. You could move the sub and also fire cannons.
Imp: The sub had an extendable robotic arm to pick up things!
And you could release a diver from the bottom of the sub. The sub would then remain
stationary as you would control the diver.

Hmm, it doesn't sound hundert percent as what you described about it, but might #2 be this one by any chance? You could also get out of the sub in it and control the diver around.
In Search of Dr. Riptide

Hmm, a good game but not the one I'm looking for. The #2 game had an actual diver (black wet suit) coming out of the sub (very sleek silver sub). You could also be eaten by sharks. The graphics also look more realistic than cartoony (Best rendition of a beluga whale I've ever seen!) (its definitely a 2d side scrolling dos game)

well, in here (to the right) there are 16 filtered games with theme `naval` and `educational` genre, check their screenshots out, maybe it's one of them

Maybe this one: Submarine Fury?

Also, check submarine games on moby...