hiya!
every working cocker is different and i'm sure that it largely what they are allowed to get used to, but in my experience with barkley (who is now 2), he is definitely a 3 walk a day kinda dog. he gets maybe an hour offlead in the morning, then between 30 minutes and an hour in the afternoon, and an on-lead 20 minute wander around the block last thing. but this is the routine that we have got him into, and is primarily because we don't have much of a garden.
the lengths of walks do vary, and if there is lots of stimulation at home, like visitors, then he doesn't need as much. but if he has a day with less than this, we definitely know about it in the evening as he becomes very fidgety.
all dogs really are different though. i know people with a working cocker bitch who gets much less- she is however very mischevious (sp?) at home, which i would put down to not enough stimulation through being out and about.
with games, barkley's favourite by far is hide and seek with toys. we get him to sit and stay, hide a toy and tell him to 'find it' and he's as happy as larry searching the house.
games like this are great for a dog that likes to think and seek things out, which workers often do.
hope this helps a bit.