This is just a suggestion, but for levels that have an "Author" field, can it be displayed under "Rating" on the info screen, possibly in the red letters used to display the level name? (I don't think there's another colour that isn't used).
Formatting should be straightforward and obvious: "Author" is aligned with "Rating", and the author name is left-aligned with whatever the rating is.
EDIT: I had pondered about an "Auto-nuke" option, which you can turn on and off in the dialogs, where the nuke is automatically triggered if all the lemmings are out of the trapdoors and the only ones left on the field are blockers, but I realised there may be situations where this is undesirable (i.e. bombing a blocker releases another due to blasting the floor away). It's more of an anti-frustration feature for beginners on, say, Tailor-made for Blockers. Would an "Auto-nuke" feature be viable under the following conditions?
- All lemmings have entered the level.
- The only lemmings still on the field are blockers.
- You have no bombers (and a blocker doesn't have a countdown over his head).