A prototype of Eurocom's Spider-Man 4 has been discovered on a debug on an RVT-H Wii development kit, giving us a glimpse of a movie tie-in (and movie, for that matter) that never was.
While Sam Raimi's Spider-Man series was commercially successful, the third outing took a bit of a beating from the critics; there were plans for a fourth movie – hence this prototype existing – but Sony would eventually choose to reboot the whole shebang with the Amazing Spider-Man movies (which, in turn, would be abandoned in favour of another reboot more recently, kicking off with Spider-Man: Homecoming).
Development clearly didn't get too far, as the prototype only has two (incomplete) stages and there's not a massive amount of detail, beyond the basic traversal mechanics and a few effects. A range of debug features are also included, presumably to aid the developers with level creation and basic design.
Interestingly, when running the ROM via emulation, it is recognised as Dead Space: Extraction, another Wii title from Eurocom (but one which actually saw release). This suggests that Spider-Man 4 was built using the same game engine.
If you fancy downloading the prototype and having a go on it yourself, you can find the link here.