Baryonic Predicament is a singleplayer puzzle-action mod for Half-Life 2: Episode Two. This mod contains over an hour worth of gameplay. Created by Miigga IMPORTANT: Turns out that some Steam update has caused this mod to not appear in the Steam games list. Worry not, simply go to the "gameinfo.txt" file that comes with the mod and add a } in the end. Restart Steam and it should show up now. Baryonic Predicament was originally exclusively released on Planetphillip.
This is the mod itself. Extract to your SourceMods folder and restart Steam. HL2: Ep2 required.