The plot is not original by any means. If you have seen any anime which features a character getting summoned to another world, then chances are you have already experienced the same basic storyline. The plot of Isekai Cheat Magician is not really any different to any of those, meaning that you will have a rough idea of how everything will play out even before it does so. Even the plot twists are predictable. You know that when one character vows to save another, then that other is bound to die. You know that if something will allegedly never happen, it will end up happening that very episode. The trope of triggering "flags" gets used quite a bit in Isekai Cheat Magician, which would be fine if it were handled uniquely or with any level of competence, but in this anime the tropes come walking up to you face-to-face so that you see it coming a mile off, and frequently enough that you begin to dread them.
The artwork and animation are one of the two redeeming features of this show. The fantasy settings may not be unique in any form, but are still done cleanly, resulting in aesthetics that very few should find displeasing, though the lack of originality may disappoint some viewers. Fight animations are smooth without being unnecessarily flashy, magic usage is likewise quite well done without many obnoxiously long chanting sessions (just one that I recall). The best part of the anime however is the opening theme. "Panta Rhei" by Myth & Roid (who also provide the opening themes of Re:Zero and Youjo Senki). It's a splendid song, but that also has the drawback of building one's expectations of the show a little too high. The song is far more epic than any scene could hope to be.
Character development in Isekai Cheat Magician is, sadly, virtually non-existent. Only in side characters does there seem to be any real development. The main characters have very little development, which is rather unusual actually. At no point do Taichi or Rin mention their surnames, even. What little is revealed about them early on is about all that will ever be revealed of them. Meanwhile, a side character by the name of Anastasia goes from being a nameless, voiceless character to having a name, back story, and various desires. More of her is explored in a single episode than for Rin or Taichi across the entire season, which seems like a very odd choice. That might actually be the only unique thing about this show.
Another problem that many viewers will likely pick up on is the pacing of some episodes. Isekai Cheat Magician falls into a trope that many anime fall into: the excessively long-winded discussions that only ever seem to take place in the middle of battle, when the pace should be fast, not slow. While anime such as Tate no Yuusha no Nariagari has scenes where antagonists take advantage of such discussions, the ones in Isekai Cheat Magician seem content to let characters continue talking for nearly half an episode before resuming the fight, which ends up being rushed in order to keep the episode within normal time limits. A lot of anime are guilty of this, so Isekai Cheat Magician has no excuse for falling into the same trope.
Over all, not a great anime. It could be much worse, but it could be so much better as well. It had the potential to be, but that potential was wasted. If this is your first experience with Isekai-type anime, then it may not seem too bad to you. If you're familiar with the premise of the genre though, then you'll likely be disappointed. If you have nothing else to watch, then I suppose this will suffice to pass some time, but to be frank you would be better off re-watching something else, even if you've seen that something else 100 times already.
