Half-Life 2 Dr. Isaac Kleiner 1 game Dr. Isaac Kleiner is a character from Half-Life 2. Verified 21 Aug 2026 Appearances Games featuring Dr. Isaac Kleiner 79 Half-Life 2 16 November 2004 Other characters in Half-Life 2 Full cast Dr. Eli Vance Alyx Vance Dr. Judith Mossman Barney Calhoun Citizens & Misc. characters G-Man Father Grigori Overwatch Dr. Wallace Breen Vortigaunt
