Konosuba is a somewhat sarcastic comedy in a fantasy setting. The anime is generally on-par with the genre average, and many new to the concept probably won’t be disappointed. Much of the strength of the anime will come from its irreverent glance at the genre and its occasionally incisive commentary.
While Konosuba’s pretty entertaining at first, it tends to get somewhat stale by the end since its comedy comes primarily from “reaction catchphrases.” Basically, the cast is composed of characters that react in one particular way to a given situation. One-off characters aren’t necessarily a bad thing, so long as the situations are odd and unique enough to make the characters’ quirks shine. Unfortunately, Konosuba doesn’t vary the settings or the situations enough to have the one-off weirdness shine the way it would with appropriately bizarre and crazy situations.
The most unique part of the anime is its twist on a “stuck in a game” setup, instead replacing it with a fantasy world functionally similar to a game. This avoids much of the problems that plague the “stuck in a game” anime subgenre. One of the biggest weaknesses you’ll find with these kind of anime is the under-utilization of the world. There is no meaningful distinction between the real world and the game world like you’d find in the one of the first to use the concept, .hack/sign or the more recent Log Horizon.
All in all, not a bad place to start, but there’s a lot better out there.