Terrytoons Studios' quality was very variable from when they first started in 1929, their first cartoon though in 1930 with 'Caviar', to the end in 1971, with the final Mighty Heroes cartoon 'The Big Freeze'. This is in regard to their animated shorts/cartoons though. They did do some decent cartoons, few great (the best of Heckle and Jeckle came close though), as well as their fair share of clunkers, never ones without redeeming qualities though even their worst.
1942 saw the introduction of Mighty Mouse with 'The Mouse of Tomorrow', or Super Mouse as he was known for until 1944. He was their most prolific character overall, before then it was Gandy Goose who became more interesting when partnered with Sourpuss, and his series of cartoons was a perfectly watchable one if not exceptional and became very formulaic quite early on. He was a pleasant enough character, though never has been one of my favourites, his personality likeable if limited and he wasn't always well used. 1944 continued the inconsistent quality that summed up all the studio's previous years batches. 'Mighty Mouse Meets Jekyll and Hyde Cat' is one of the high middle ones to me, amusing and atmospheric but lacked the extra spark that it could have done considering it had one of the best premises of the Mighty Mouse series.
It is a very old premise and a very done to death one, but it has never at the same time lost its intrigue and entertainment value because the Robert Louis Stevenson story is such a timeless one. 'Mighty Mouse Meets Jekyll and Hyde Cat' has enough amusement and creepiness, but it missed the opportunity to do more with the premise and there is not an awful lot new here apart from the characters. Outside of the basic idea, the story is a pretty standard Mighty Mouse story albeit in a different setting.
Mighty Mouse, considering he's the lead character, could have been used better too. Like he can be, he is underused and when he does appear while entertaining it has nothing really new to what he did in his previous cartoons. He is fun and likeable though and his bravery is admirable.
However, the music continues to be the best asset, like it consistently was in all the Terrytoons cartoons at this point of their filmography. It is beautifully and cleverly orchestrated and arranged, is terrific fun to listen to and the lively energy is present throughout, doing so well with adding to the action. The animation, having come on such a long way from being a weak point to the most improved component, impresses too and shows how much the studio had advanced on a visual level. It is nicely detailed, lively and colourful without being garish, the creepy atmosphere it has is also striking.
There are amusing moments and the transformation and demonic cat form are genuinely freaky. The mice have more to them than just looking cute, but the most interesting character is the cat who also has the best moments. Do agree too that the narration is a major strength here, never corny or over-explanatory and the delivery unsettles.
Overall, decent. 6/10