To expand a bit, Kill la Kill feels very self-consciously retro, an homage to a very '90s style of anime that's much more cartoony than today (it owes something to Needless which I looked up and found to be more recent than I expected - I can only assume that was itself a retro effort?). There're a lot of exaggerated visual effects (think heads expanding to 10x usual size), limited animation tricks (cyclic eating motion, speed lines); a few of the visual touches are quite clever clever (using a square aspect ratio for the sepia-tinted flashbacks) and it obviously looks a lot better than the animation of the era it's echoing, but I'm not sure how it objectively stacks up against modern style. The plot is deliberately ridiculous and over-the-top, and the show's pretty heavy on fanservice (admittedly integrated closely into the plot, but it still feels like a lot of gratuitous nudity). As well as Gurren Lagann it reminded me of Mysterious Girlfriend X - different genre, but the same retro fanservice style.

The overall impression was reminiscent of Grindhouse - "ok, you've crafted an excellent pastiche of this old style - but actually we abandoned that old style for a reason". I found Kill la Kill very fun to watch at the time, but it hasn't stayed with me since.