when playing a new level, is your 1st action...

[LJLPM]

... pausing the game? (to quietly take a look at the level, and think about your strategy)
Personally, yes. I like to have an overview of a level before tackling it.

[ccexplore]

It's hard to imagine "just dive into it" working too well once you get to harder levels.  When you're in easier ratings with 20 of everything, just-dive-into-it is quite reasonable to do.  Once you are in harder ratings where often almost no skills can be wasted, I'd imagine that after a while, by habit you'll probably want to pause and take a look first.  Even if you do end up having to "just go at it" on certain parts of the level (particularly the places where you haven't quite figured things out yet).

I imagine this would especially be the case when we're talking about the actual games where replays do not exist.  It's possible that with replays being a pretty common feature in the various Lemmings clones people have made here, just-dive-into-it could become more workable again even for hard levels.

[Clam]

I always pause at the start. This habit carries over from strategy games where I do the same thing (only in single player mode of course . Side note: I'm really glad Lix multiplayer disables pause completely ).

In Lix with the option of unlimited time, it can be nice to have the lix start in a holding pen so you can strategise without pausing and start solving when you're ready. This certainly isn't a requirement for good design though (not least because it limits your options).

On the other hand, I do think it's more than just "nice" if, once you do decide to dive in, you can reasonably execute the solution without further pausing.

[Prob Lem]

I always pause and take a look around at the start of a level, too. The preview images rarely give enough detail to not necessitate this.

[mobius]

On the *very* first playthrough of a level, I do not pause, I just let the level begin and do nothing to see what happens while I think. I found this helps in certain situations.
As an example I've heard people say things like "I spend hours planning out a route only to discover etc, like a hidden trap or something. Playing and trying things out is also more fun imo than just staring at the screen.