While plenty of games have been very clearly inspired by Super Mario 64, SPRay might be the first that's drawn so directly from the underrated Super Mario Sunshine.
There is little argument that the overall quality of third party titles for the Nintendo Wii is generally lacking. All consoles have their share of shovelware, but the amount for the Wii seems disproportionately high. Indeed, for a few generations now, Nintendo consoles have been largely identified by their extraordinarily polished first-party titles, and little else.
While plenty of games have been very clearly inspired by Super Mario 64, SPRay might be the first that's drawn so directly from the underrated Super Mario Sunshine. The use of water as a gameplay mechanic is taken from Sunshine, and extended to encompass a variety of liquids, each with their own specific purpose for puzzle solving and combat. While the inclusion of liquids like slime, for example, are easy to understand, it is a bit more difficult to see why it was felt that vomit would constitute a welcome addition. There is certainly room in video games for puerile sensibilities -- the issue is that in this particular game they seem to be present solely to endear the title to younger gamers, and surely there are more charming ways to do so.
Every genre of game has some core elements that contribute so fundamentally to the overall experience that it is nearly impossible to overcome substandard implementations of those elements in a given example of that genre. For platformers, it is very difficult to look past unintuitive controls or an uncooperative camera. Unfortunately, SPRay falls victim to both. While Super Mario Galaxy has demonstrated that smart, intuitive controls are possible for platformers on the Wii, very few titles have felt as comfortable, and SPRay is not one of them.
Much like controls, in order to be characterized as successful, a game's camera should be something the player rarely, if ever, has to think about. The camera in SPRay, however, is neither smart enough to perpetually provide the best possible angle, nor does it allow the player enough control to adjust it when needed. It can be remarkably frustrating to have to fight view and perspective issues while trying to negotiate the kinds of obstacles that platformers generally demand.
It's not as if SPRay is devoid of enjoyment. The addition of multiplayer to the title is certainly welcome, if not necessarily creatively implemented. While there is a multiplayer component to the main game wherein one player controls the protagonist, and the other is in charge of spraying the liquids (similar to the mechanic of Super Mario Galaxy where a second player could use a Wiimote to collect Star Bits), the competitive modes probably have the most potential to make SPRay a more worthwhile package overall, particularly since each is based on the unique characteristics of a particular liquid. In practice, these modes are exactly the type of minigames that are far too abundant on the Wii already. But they are arguably a much more enjoyable way to play the game with others, and as such it's difficult to complain too much about them.