Last week in a fit of nostalgia spurred on by Shovel Knight, I picked up Castlevania 3: Dracula's Curse as well. It's a classic of the NES era, and I was happy to pay $4.99 to experience it again. But twice that amount just to have it across both of Nintendo's platforms? No thanks.

Nintendo has made some strides in its online services lately. The Nintendo Network ditched the separate stables for console and handheld and lets players use one account, with shared currency, across both platforms. Mario Kart 8 had some forward-thinking ideas about sharing videos. With so much ground gained in the last few years, why hasn't it caught up with an initiative that Sony has been running for almost two years?

When it was introduced in 2012, Sony's cross-buy system seemed revolutionary. One purchase gains you a game across multiple parts of the PlayStation eco-system. Sometimes it even extends to more than two platforms, as games are available across PlayStation 3, PlayStation 4, and Vita. The initiative is arguably one of the few things keeping Vita afloat as it flounders for new content. After two years of precedent, though, cross-buy seems entirely ordinary. Gamers expect it, and feel put out when a publisher charges separately across PlayStation platforms.

Publishers seem chastened, even apologetic, in response to fans wishing for the functionality. In cases when it does happen, Sony must be brokering the terms in some way. Nintendo's own shaky relationships with publishers may make the company reluctant to put itself in a similar position.

Whatever the reason, that decision is hurting the appeal of its platforms. Just as cross-buy has helped bolster Vita, a similar effort could be a boon to Wii U. Even if limited only to Virtual Console games, imagine if your library were shared across devices. No more purchasing classics like Super Mario World or The Legend of Zelda several times. You've bought it, you own it, and you'll be able to play it on your new systems too.

Nintendo has taken tentative steps in this direction. It offered an upgrade program on Wii U that would let you play Virtual Console games directly through the Wii U interface, instead of the "Wii Mode." You would have to upgrade already-purchased games for $1 or $1.50, but that's certainly much more generous than repurchasing them entirely. If Nintendo can manage to be even slightly more generous, it would make a massive difference in both how they are perceived, and in the libraries of their customers.

Just today, as I was planning to write this, we learned that Nintendo has taken yet another step forward. Gamasutra reports that in Europe, the third-party game Squids Odyssey is cross-buy on 3DS and Wii U. You'll need both devices to be registered with the same Nintendo Network ID, for obvious reasons.

This is in many ways a massive step forward. Not only is a game finally using the functionality, but it's a third-party game at that. But it's also very limited. This is only one game, in one region, and the announcement didn't detail if we're going to see more efforts like it. For a functionality that should have been offered across all Virtual Console and some new third-party releases by now, a single game is incredibly incremental.

Now is the time for Nintendo to send a clear message that Squids Odyssey isn't a fluke. If this is a sign of a future trend, as it should be, the company needs to say so. We should be hearing detailed plans for how this will be implemented, both for future releases and retroactively on older titles. If this remains relegated to a single European release, that doesn't bode well for Nintendo's commitment to the idea on the whole. It's already late to offer cross-buy, and we need to see a sign that it won't continue to drag its heels.