14 years on, it might say more about me than about games that I automatically want to reference Portal when I play a game like Claire De Lune. It's a bit unfair to compare everything in the first person physics puzzle subgenre to one of the best games ever made as a default.
You have a zappy non-violent gun necessary for navigating a series of platforming challenges. That's... actually where the similarities end. Instead of the increasingly sinister laboratory and wry humour, Claire De Lune crashes you into an alien planet and asks you to reunite with your daughter while periodically getting a flash of sad backstory.