This is one of those literal examples of a short and sweet game. Now, there will be spoilers so if you haven't played or seen a walkthrough of the game, stay clear but by all means, do play it!
It tells the bittersweet tale of a young woman's relationship with her lover, spiritually and physically. Spiritually because you realize at the end of the game that he's dead and the whole game recounts their happy and dark memories up until the end. It is a deep, complex story that takes her through the journey of grief as she moves towards acceptance.
The little moments in their relationship is beautiful and it really makes you feel for these characters once you know what has happened between them.
I also love how the story actually has a moral unlike most games. It is relatable to anyone going through grief, not just anyone who's lost a lover but anyone who's lost any loved one, whether through breakup, divorce, or death. It teaches you that life goes on, don't give up on the things you're passionate about just because someone you loved who may have influenced your life in some way has passed away. You must have hope to carry on. Eda, at the beginning of the game and implied in the past, is poor at playing the violin. The owl (her boyfriend) was the one who taught her how to realize her talent. Eda at the end of the game learns that even though her boyfriend is gone, she still must keep her passion and talent to play the violin.
Most of the puzzles in the game are relatively simple but there were a couple ones I did get stuck on so you should have it relatively relaxing time in general if you don't want something too difficult. Though, I did have to look up a walkthrough for one part and it does require a couple of scrutinizing attention in a few parts, so keep that in mind if you're not a hardcore puzzle gamer.
I also love the pastel art for this game. The cute character designs reminds me of a mix of like studio ghibli type anime and a western cartoon design. The animation consists of different character shots rather than actual movements, I don't know if I'm explaining myself clearly but it fits nicely with the quiet, silent, relaxing tone that this game has. I just loved looking around the room just to look at the beautiful designs.
Now, it was hard for me to interpret all the symbolism. I'm not much of an analyzer but here's a good analysis of the game. https://sea.ign.com/when-the-past-was-around/164709/feature/the-meaning-behind-when-the-past-was-around-and-why-you-should-experience-it-yourself
Overall, this is a great game for anyone going through grief and learning how to move on and I thank Nintendo's indie world for introducing me to this game. It really deserves more attention.