With those distorted sounding vocals, the music of Oliver Ghoul has this indie rock vibe to it which can feel trippy/psychedelic and like we are in space at the same time. There aren't really a lot of artists to compare this with because while there are pieces of a band such as Cage The Elephant in here, there is also something else which just takes to this other place-- there is this other layer to it.
At one point the song breaks down into soft tones, getting quieter, and then it comes back with big keys that sound like sirens but still those funky guitars remain. This reminds me in some ways of someone such as Gnarls Barkley, but it's really just such a combination of different aspects of different sounds that it forms its own sound.
While the sound of Oliver Ghoul can be guitar-driven, it doesn't sound like a guitar and can almost feel like it's a pop rock song but also that trippy quality remains. During this music video, there is also a ghost present and with that these whirrs come through and can make this song feel haunted at the same time. Regardless of being able to say "This sounds like Artist A + Artist B", I think there's just some other element I cannot put my finger on.
Back in the early '00's I think the genre known as "college indie rock" really kind of went full bloom. Bands like Snow Patrol were taking over the radio and bands like What Made Milwaukee Famous were also out there, less discovered perhaps. Oliver Ghoul would've fit perfectly within this scene, with this unique sound that is a reflection of bands such as Silversun Pickups but also just such a force all its own.