Despite the game taking place in America, the cars are the same Eastern European cars from Half-Life 2 which takes place in Russia or Bulgaria,
A scripted event near the beginning of the game serves as an introduction to the Barnacle enemy. A classic Half-Life enemy that latches to a ceiling and uses a dangling long tongue to grab and eat anything that walks under it. Similarly to the one in Half-LIfe 2, this tutorial attempts to explain how the enemy works and what it does so that players know how to deal with them in the future. This is the only time this enemy appears in the game.
After escaping a collapsing Nova Prospekt Mitchell arrives for whatever reason in a forest in complete daytime where he is told by the G-Man that he was manipulated into attracting the attention of the Combine to make an easier path for Gordon. Ignoring the fact that the Combine refer to Gordon as "Anticitizen One", the Combine teleporter breaking causes Gordon to go missing for 2 weeks, something which the G-man of all people should know. G-Man also says "Black Messa" again.
In the Black Mesa cut-scene you can see a Black Op trying to attack Mitch with a knife... Black Ops will never go for direct confrontations... rather attacking the player from a distance with either a grenade or a gun Unless they are forced to if the player comes close and even then they try to kick you instead of stabbing you.