I have a bit of a soft spot for whimsy, so when I cracked this open with basically no context for what it was, I was happy to find a fun slice of life story about 4 high schoolers playing with kids toys. For a 21 (and 2 extra) chapter read, this series provided a light, enjoyable experience for the time that it took.
Those familiar with Dagashi Kashi might find this appealing for its similarities - and indeed it has a few. In both execution and premise, Bandai Kaname wa Asobitai is very close with Dagashi, but it is inferior. Characters in Bandai have
less time to develop and are more one note, whereas Dagashi both has longer to develop, and better written characters. Bandai has average art, and Dagashi has great art. Bandai barely has a story, whereas Dagashi has time for both story and fun.
What I'm trying to say is this: Bandai Kaname wa Asobitai is a fun, whimsical, nostalgic romp that you can read in 3 hours. It isn't amazing - nothing to write home about - but it's the kind of series that you can enjoy despite that. But, if you're tight on time to read, I'd encourage that you try Dagashi Kashi before coming to this. However if you've either already read it or have the free time and you find the description appealing, you probably won't regret it.