I find that with my ducks, you have to entice them to come play with you. Think of the difference between chickens and ducks like the difference between dogs and cats. My chickens love to be picked up, petted, smooshed, whatever. My ducks, on the other hand, like to come to me for attention on their own terms.
I started both batches of my ducklings using the same methods, and I now have a nearly grown lap drake, 2 cuddly babies, and the rest love to be near me, are OBSESSED with nibbling on my hands/clothes, and occasionally want to be petted. Not bad odds out of 9 ducks!
What I did was I made a point of picking up each duck gently once a day. More for the ones who obviously want to be picked up. They will run initially, but it gets them to understand that picking up=nothing terrible happening. It might even mean something pleasant! hehe Then, I visit them numerous times a day and just sit near their brooder and talk to them. Look at their little faces, they will look at you, too.
Also, occaasionally put your hand into the brooder, very slowly and gently, and just leave it there next to the wall. It sounds loony...but try to "radiate" kindness and gentleness to them. If you think that way, it subconsciously makes you "seem" more that way to the ducks. They are very intuitive creatures, they pick up on these subtle things.
Just continue doing this as your routine. Make sounds similar to what they do when you are around them...justdon't make the high pitched terror shriek they do when they are horrified.
It makes them feel more connected to you. Something all my ducks enjoy once they are used to my presence is playing with my fingers. I just offer my hand extreeeeemely slowly to the scared ones palm up, and try to touch the beak tip with my fingers. Very gently. They might run at first, but just let them go, never chase one. In fact, if they DO run, move your hand back, too. If they don't run, just lightly touch or rub their little beak tip, and their entire beak if they allow you. ALWAYS offer your hand at a lower level than their heads, and NEVER come down over them, it terrifies them. Eventually, you will have little mobs of duckys nibbling on you when you turn your back!!