Hey looking cool! I like that you’re incorporating an anticipation for that strike. All the elements are in and I’d say just start playing with lifetime, and size and really nail down a nice snappy timing. I don’t have a clip of mario kart up so I don’t know what the ref looks like, but I would literally frame by frame through the original reference, and count how many frames each element takes to complete, or how long they are on the screen, and their relative size to each other. No harm in precisely dissecting and copying a reference like this especially if your looking to duplicate it for personal work!