It’s difficult to memorize the past participle, but this karuta game hopefully makes it a little easier (and more fun).
Make a list of irregular verbs to be used in the game. My list has 28 verbs.
Make 2 sets of cards – the yomifuda (reading cards) with the present and past tenses & the torifuda (karuta cards) with the past participle. It helps to color them differently.
I played it in 2 lessons.