I just replayed Hard Hat Mack again today and remembered there's something that's puzzled me for years. In the first level, there are four holes in the platforms that you need to fix by dropping in a iron bar and screwing it in place with a huge roaming screwdriver. The thing is, if you pick up the screwdriver you can't put any more bars in place, and I've never quite figured out how to drop the screwdriver. And it's tricky to avoid it until you've got all the bars in place, not to mention that if you die, only bars you've finished screwing in stay where they are.
So what I'm wondering is: how do you drop that screwdriver again if you took it too soon and need to pick up more bars? Is it even possible, or are you forced to suicide if you run across it too soon?