Japan's military has released a smartphone game featuring cutesy characters who dodge household objects, marking the latest effort to polish the force's image and lure new recruits.

The game, launched last week, calls on cartoonish figures in military uniforms to protect a home while the owners are away, including crawling on the floor and piloting a jet fighter to avoid flying objects including apples.

Called Jieitai Collection, the game can be played for free on iPhones and Android devices with new missions to be launched on the application every month until June.

Pacifist Japan's Self-Defence Forces (SDF) launched four promotional videos for the game on YouTube with the tagline "Be an SDF official and protect your home!"

"We want people in a wide age group to learn about what SDF officials do," a defence ministry spokesman said.

The game is part of efforts to soften the image of the 230,000-strong force, which saw the number of applicants for positions fall 10 percent in 2014 from a year earlier.

The new game has not been without social media critics, however, who have said it is too tough to play.

The cute and cuddly approach is in sharp contrast with a videogame released by the Chinese military in 2013 which let players fight enemy forces in islands disputed with Japan -- echoing a real diplomatic spat that has marred relations between the Asian powers.

In another image-bolstering effort, the SDF earlier this month put officers on the runway as models at Tokyo Boys Collection, a fashion event dedicated to supporting victims of Japan's earthquake-tsunami disaster in 2011.

In 2013, the maritime forces launched an online campaign inviting the public to vote for their favourite personnel via smartphones.

The military is also involved with a magazine that features female models posing in military uniforms.