It really was amazing that the Popeye series was still going solidly in the early 40s, considering Fleischer Studios suffered a significant decline that affected the cartoons produced in this period quite badly (the worst of them were quite weak and there were a lot of average efforts). The Popeye series was the least affected by this and even the weakest early-40s Fleischer Popeye cartoons were more watchable than most of the studio's cartoons from this period.
'Onion Pacific' is no exception. It is nowhere near close to being one of the best of the Popeye series, it is not on the same level as the best of the mid/late-30s output (one of the studio's best and most consistent periods, the odd disappointment aside). Where the best from that period were among the studio's best work in my view. It is also nowhere near close to being among the worst, it is much better than the 50s output at its worst where the decrease in quality was vast.
There are things that could have been done better. It could have done with more freshness, with a story that is pretty formulaic and basically standard Popeye vs. Bluto. One knows from the title alone how the cartoon is going to end.
Pinto Colvig, the original voice of Goofy and somehow it was hard to get that out of my mind, never really did it for me as Bluto. Not sinister enough and didn't sound he was having as much fun as the character's other voice actors. Other than being a reason for the action to happen, Olive didn't serve an awful lot of point here.
However, the animation is great and makes for one of the best-looking 1940 Popeye cartoons. Love the attention to detail in the backgrounds and Popeye's character animation, and compared to the series in its early years to me the animation quality advanced quite a bit for Fleischer regarding the late-30s onwards Popeye cartoons. Some of it, even in the busier moments, were quite inventive. The music is another high-point, that was something that was consistently never less than excellent throughout the entire Popeye series (for both Fleischer Studios and Famous Studios). Very lush and characterful, adding a lot to the action.
Which comes thick and fast, as does the energy, capped off by a wonderfully wild final third. Despite the formulaic story, it never felt dull. It also is never less than amusing, the gags are numerous and although they are not novel they are still clever and didn't feel stale. The one with the bridge is particularly good. Both Popeye and Bluto are compelling characters, Bluto having funnier material, with good comic timing and strong personalities. Jack Mercer as always nails it as Popeye, those asides and mumblings are priceless.
In summation, not quite great but still entertaining. 7/10