Maruruku-chan no Nichijou (Marulk's Daily Life) is a series of shorts about Marulk's daily life (quite self explanatory). It's a simple and fun short eps that play before the real show: Made in Abyss: Dawn of the Deep Soul, making it a really good palate cleanser before the main meal.
The four shorts are just about Marulk's daily life helping Ozen around. Seems simple, but Ozen being despicable and Marulk being innocent makes it a bit more fun. The first three fit this format very well, and just show Marulk messing around and being a bit too innocent about what happens around him. The fourth short
shows his backstory, and takes a bit of a turn compared to the other three.
As it's part of Made in Abyss, the art is the same as the rest of the series, and is done well, bringing out the emotions of all the characters well. Being a spin-off, obviously it doesn't get the same attention as the main series, and therefore, there is no stunning music by Kevin Penkin, but that doesn't mean it's bad. Naomi Niu does a good job with this fun and lighthearted shorts.
Characterisation was done well, as we get a better understanding of what happens in the series when we're not following Riko and Reg (and Nanachi and spoiler) down in the abyss. Of course it's not as in depth as the main series, but we see the real show: how they act normally, and that's what makes the characters here great. No flashy characteristics. Just Marulk's innocence and Ozen's mischief.
Overall, this is a great way to start off the Made in Abyss: Dawn of the Deep Soul movie. It gives a nice palate cleanser before the film actually starts, and is just a fun and easy thing to watch, which is definitely required before you get to the real show. Trust me, you're going to need it.