That was a very enjoyable experience from start to finish! Well, barring that time the downloaded version crashed on me, which happened after I talked to Gilbert the first time; I'd been collecting the quarters and tried to click and use them on him, but the icon was that of my whistle and when I clicked on Gilbert, the game threw up an error screen. I switched to the browser version, which worked fine... though that may be because I avoided doing the above.
That aside, the game is obviously well-crafted and the pixel style is great: The environments fit the game perfectly and are filled with humorous asides and the character sprites are filled with personality. The GUI works excellently and has a friendly, chunky feel without being too "kiddy," and I think both the writing and the gameplay is accessible and enjoyable for actual kids as well as older players... though most kids probably won't get a lot of the references. I especially enjoyed your writing, which was witty throughout and absolutely nailed the pulpy crime/film noir style, which is easy to parody but difficult to parody well especially in an all-ages way. The BGM fit the atmosphere perfectly and I was genuinely satisfied after solving the final puzzle; the puzzles themselves were pretty straightforward, but that's probably more accessible to people who aren't familiar with the adventure game genre.
The game may be short, but I had a lot of fun with it. Thanks for making it available!