Smartphones now come with vast amounts of storage — if you're willing to pay extra, at least — and the thought of using physical media with one sounds anachronistic in the extreme. But Japanese startup Beatrobo thinks that we've lost something in the transition, and has produced the Pico Cassette to fill in the blank: it's a video game cartridge that you can plug into your phone's headphone jack.

"Sure, you can get Chrono Trigger on your iPhone," Beatrobo founder and CEO Hiroshi Asaeda told me at Tokyo Game Show. "But it's just not the same." Asaeda believes that you don't get the same sense of ownership with an app on a home screen as you did with a SNES cartridge on yourself; Pico Cassettes are meant to spark a similar nostalgic feeling.

The cassettes, which look like mini Nintendo Famicom carts, are an extension of Beatrobo's PlugAir technology, which has been used to sell physical music and video content at Lawson HMV stores in Japan. The cartridges don't actually store any software themselves; instead, each acts as an authentication key by sending out inaudible sound. You'll still be interfacing with an app to download your content, then.

But the physical nature of the cartridges has more to offer than just retro appeal. Since each device has a unique identifier and can communicate with Beatrobo's servers, you'll be able to keep save games and play each title on multiple devices; the easy portability could make you feel more like the game really belongs to you than with digital titles. If nothing else, it'd probably be more reliable than iCloud game backups.

At Tokyo Game Show, the only playable Pico Cassette game was a simple proof of concept that Asaeda fully admitted was a Flappy Bird ripoff. But he says that Beatrobo is working with content partners, and plans to bring Pico Cassettes to market soon following a crowdfunding campaign. If the crowds at his company's small booth are anything to go by — far bigger than for any other startup I saw at TGS — there's quite a bit of interest in this quirky idea.