The gameplay in Okaeri! Chibi-Robo! Happy Richie Ōsōji! is similar to the original Chibi-Robo!. The player takes control of the titular character, a 10 centimeter-tall robot whose job is to clean the inside of a house to make his family happy. Chibi-Robo is owned by Jenny from the previous game, who is now all grown up and living in a house with her son Keith and dog Lucky. The game introduces a tiny vacuum cleaner that Chibi-Robo can use to suck up dirt while connected to a power outlet and a tiny sifter used to find gems which can be turned in for money. The player can use the money to buy furniture for the house over a home shopping network using the telephone. The main difference from the original games in the series, is that instead of just having power outlets which let the player charge Chibi-Robo's battery, they need to put rubbish into a trash compactor to get electricity for the outlets.
The game received a high 34 out of 40 from Weekly Famitsu magazine in Japan. It was the fifth best-selling game in Japan during the week of its release, selling 35,000 units. It fell to number nine the following week, selling 23,000 copies. Regional sales of the game totalled 130,092 units in 2009.