Cross-buy — buying a version of a game for a platform maker's console and getting it free on the handheld, or vice-versa — has been a feature of many games in the PlayStation family. So far, the only concessions Nintendo gamers have gotten for games that release both for the 3DS and the Wii U have been discounts for buying the second version. There are signs that may be about to change.
Those who buy Squids Odyssey on the 3DS will be able to get the game on Wii U at no extra cost, but so far this offer is available only in the European eShop. Furthermore, buying it on Wii U does not offer a free 3DS edition, so those with both platforms need to be careful which one they purchase first.
Late last year, the 3DS adopted the Nintendo Network ID, allowing for a single account to manage purchases on both it and the Wii U, conceivably opening the door to this.
Recently, 1001 Spikes, by Nicalis, launched on Nintendo 3DS and Wii U; it did not offer cross-buy support but it did cut its price by $5 for anyone who bought one of five other Nicalis titles from the eShop.
Update: Squids Odyssey developer The Game Bakers told Siliconera that they approached Nintendo of America about this type of cross-buy sale, which Nintendo apparently calls "conditional sales," but were told that NOA "could not support this operation yet." Polygon has reached out to Nintendo of America for additional comment and will update this post with any made.