The slime becomes way too strong
That Time I Got Reincarnated as a Slime, released in Italy as Vita da slime, is the animated series produced by studio Eight Bit and broadcast from October 2018, based on the light novels by Fuse and illustrated by Mitz Vah, published in Italy under this same title in their comic edition as well. It tells the story of Satoru Mikami, an office worker killed during a robbery who wakes up in a fantasy world in the body of a slime, takes the name Rimuru Tempest and soon finds out that the place he has landed in has no intention of leaving him alone.
Along the way he always carries with him his dangerous, draconic friend, absorbed in the opening dungeon to help him break the barrier that was keeping him prisoner: Veldora Tempest. It was the mighty dragon who gave him his first name and who passed his power on to the slime.
The series is made of adventures that build on one another and focuses mostly on the places of the Jura forest, in an almost self-contained setting. Its levelling mechanism is rather linear, with characters becoming exponentially more powerful with every story arc. That drains almost every combat mechanic: after a couple of seasons the main character finds himself all but unbeatable.
This is one of the main flaws of isekai anime (and it holds for some battle shonen too): either the hero starts out far too powerful, or he becomes so along the way.
Still, I can say that the first season is genuinely fun, with plenty of adventure and plenty of exploration, and that it has a driving rhythm and a driving score. The adventures in Ramiris' labyrinth and the fight against the orcs were the most interesting parts, because in the meantime they were opening up subplots as well.
This is one of the anime that aired after the big four isekai (Overlord, KonoSuba, Re:Zero, Tanya the Evil). It is a decent anime, well worth a watch, but be aware that the seasons after the second one have a slower pace.