I do approve of there being the two of them though. 

 

Most of my favorite games don't have introductory levels, OR i first played multiplayer, iirc:

- descent: none, easy start level though
- magic carpet: no? slowly gives you spells though...
- syndicate: nothing at all.
- Kingpin: easier start level?
- diablo 1: no, sir
- quake: has the skill selecting, but i wasn't impressed. MP first for me.
- hl: has the train ride (which i still find impressive), but MP first for me.
- quake3: well.. :-)
- pod: well, it starts out with easy tracks
- super metroid: has one, but it left a sucky impression on me.
- far cry: has a short, shitty one, and the game took my breath once the tutorial was OVER.
- freespace2: has in-depth tutorial, but it's a very complex game, and totally makes sense because it's basically a military simulator and this is your training.
- dungeon keeper: has one, but it's a complex game that has fundamental concepts that are hard to demonstrate without explicit introduction. Even is too long, so that there are not enough levels where you can use all features of the game
- resident evil 4: i can't remember?!
- silent hill 2: not sure, i can't remember anything like a tutorial.
- sacrifice: hmm, you have a mentor/advisor at your side during the entire game

Those are all that come to my mind right now :-) 

Quake 2 had a pretty good first level. It effectively introduced ladders, crawlspaces, destructible environments and multiple routes within the first five minutes, most of which were rare if non-existent in most FPS games at the time. 

New to iD games maybe but not FPS games :p 

Will modify my statement, and accede to the correction.

SG = sniper rifle, not pistol

SG is useless...for the way I enjoy playing.

I feel like it slows things down and makes it more about sneaking as opposed to fast paced aggression.

Horses for courses. 

I'm a big fan of the first level functioning as a "natural" tutorial, where the player is introduced to concepts in a gradual way, but the level is a real level that's part of the character's mission/story, and not some "training room" where you shoot mannequins.

Some examples from games:

Quake 3's entire first episode was sort of a tutorial where they start out with a tiny flat map with no loops (and a teleporter tutorial), and slowly add loops and overlapping paths etc. in the subsequent maps.

Metroid 1 started with the player trapped in a small 6-7 screen corridoor, where they cannot progress without collecing the "round ball" item so that they can roll through a narrow gap. This teaches you that that the game scrolls both left and right (unlike previous games like super mario brothers) and a introduces the concept of items opening up access to new areas. As soon as you get the round ball you can't even leave that screen without using it to roll under a large obstacle.

The first level of Prince of Persia teaches you about false floors in the very first screen -- you can't even leave the screen without triggering it, and they force you to drop down onto the lower part of the screen, which causes the floor panel to rattle a little, helping to show you it's there. The third screen teaches you about pressure plates that open up doors.

I realize this is a bit of a derail since the thread is actually about making a good impression / hooking the player in the first level. 

i think it's tough to replicate the formula for a great starting level, because I think the really great examples (e.g. Half Life 1) mainly serve to showcase what a breakthrough game it is you're about to play.

So
step 1: make breakthrough game
step 2: encapsulate the awesome new stuff in a short opening section

Beyond that, I'd say the other factors are pretty banal... hook them with the story, an exciting set-piece, some nice characterisation, some full-frontal nudity, whatever. 

- super metroid: has one, but it left a sucky impression on me.

When did you play it?
And also it introduces the "bad guys" and the conflict which sets a direction as opposed to just dumping you in an alien world to explore (which would be pretty cool too...). 

http://www.youtube.com/watch?v=Zgkf6wooDmw 

Quite late indeed. And i'm pretty sure i saw the game in its later stages before, and then started it on my own. I basically didn't (and mostly don't) care for story the slightest bit.