HL2: Episode 1 begins right when Half Life 2 ended, but it's a standalone title, so you don't have to own HL2 to play it. Although the game is short, it has some great gameplay mechanics, the story is very well written, it helps deepen the immersion of this journey even more. For the majority of the game you play alongside Alyx, you can complete the whole game firing a single bullet for the achievement 'One bullet', which means you have to rely on Alyx's shooting skills, with Freeman only be able to use the crowbar, gravity gun, grenades and rocket launcher. Overall Episode 1 serves as a great expansion and there's no reason to not give it a shot if you beat HL2.

https://youtu.be/MnyraDk1Mho

HL2: Episode 1 begins right when Half Life 2 ended, but it's a standalone title, so you don't have to own HL2 to play it. Although the game is short, it has some great gameplay mechanics, the story is very well written, it helps deepen the immersion of this journey even more. For the majority of the game you play alongside Alyx, you can complete the whole game firing a single bullet for the achievement 'One bullet', which means you have to rely on Alyx's shooting skills, with Freeman only be able to use the crowbar, gravity gun, grenades and rocket launcher. Overall Episode 1 serves as a great expansion and there's no reason to not give it a shot if you beat HL2. https://youtu.be/MnyraDk1Mho