Kamen Rider SD Kaiki?! Kumo Otoko, Kamen Rider Den-O: Imagin Anime Recommendations
Has a similar premise; taking Kamen Rider characters, rendering them super-deformed, and placing them in all manner of wacky hijinks. Focuses on the ten Showa Riders rather than the Imagins of Den-O, although a few (Amazon, Stronger, #2, Shin) are limited to cameos. However, KRSD is one long episode as opposed to several short ones, and has much better animation (despite looking very '90s in terms of art style).
OVAs parodying Kamen Rider franchise, redesigning the characters with chibi artstyle and putting them into comedic situations.