The mod brings nothing new to the table, using the same formula as the game it's made from. However, this is by no means a bad thing, as it does it well.
The level design does a good job at capturing the Half-Life 2 feel, and though familiar none of it comes off as bland. For the most part, the combat is easy, with some notable exceptions when nearing the end. Puzzles are scarce and and all involve opening up the path forward, so they come naturally rather than feeling like an obvious set-piece intent on stumping the player (though I might have been playing these games for so long it's become second nature to me).
Overall this is a solid if short experience and the only thing I found lacking was that there was no voice work for a character you meet near the end.