The Wikipedia entry for the band describes them as "instrumentally quite ambitious", which rather undersells their individual and collective technical abilities combined with the incredibly deft and exciting arrangements they come up with. 'Hit Me' is a perfect example and is, by some distance, the most ambitious songscheme to date.
The first thing to say about the songscheme is try not to be put off by the sheer volume of chords. What you are seeing is the 'forest' rather than 'seeds' of the song; it is, in essence, based on very few chords but with many added substitutions and chromatic moves that add real excitement to the overall arrangement. I have taken a few liberties in adapting the chords to guitar but the arrangement is faithful to the original, with, I think, every chord featured included in the scheme.
The song has based in 'G' with a brief modulation up to 'Eb' in Verse 3, before returning to 'G'. The difference here is that in each case the progressions are based on G Lydian, then Eb Lydian modes respectively, rather than the Major scale. Lydian is still a major mode but is characterised by a raised 4th degree, so in the Chorus the bass line moves 1-2-3-#4 (G, A, B, C#) and this accompanies diatonic chords from the same scale G - A - Bm - Asus4 (I, II, iii, IIsus, or IV, V, vi, V if you prefer to think of the G Lydian is a derivative of D Major). This remains consistent for every chorus in the song. The verses are based on an even more economic move from G (I) to F#m7#5 (vii) returning, sometimes, via Bm7 (iii). As mentioned this progression modulates to Eb (I) and Dm7(#5) (vii) in verse 3. In essence, that's the song, but, there are many additional substitutions, symmetrical and whole tone cycles and step-wise chromatic movements, often in very quick succession and so I'd advise working through each section carefully if you want to play it.
This track really is a brilliant example contemporary pop/ dance track that features rich harmony. The songscheme is below or you can download a hi-res PDF if you prefer here. A note on the use of colour (for the first time!) this is just used to make the various alternate endings standout given the dense nature of the scheme. Go pink at the end of the choruses to get to verse 1 and 2, Go green to go to the bridge, go orange to go to the outro.
Here is the video to accompany the track, given the variety of endings used here, this is the full track and I have not abridged any sections.