I had to play the game for an extra 20 minutes or so to finish the main story, but I managed to make it. My overall opinion of the game is that it is very uneven. Some parts were hilarious and then in others it seemed to drag on with a by-the-numbers rpg plot. I caught several cute references to some classic jrpgs (at one point you have to rescue a chained-up general who was questioning the wisdom of the antagonist empire - just like in Final Fantasy VI, at another, your goofy technician friend rebuilds a scavenged robot in a clear callback to Chrono Trigger), but none of these rose to the level of parody. They tended to tread the uncomfortable line between homage and the shameless recycling of some of the genre's most memorable scenes.
I think the best summary of my feelings for this game is that I really liked the characters, but couldn't care less about the plot. My favorite missions were in the early parts of the various chapters, where they're still establishing the characters' quirks and relationships and which feature minor, eccentric villains to give them something to do without advancing the plot too much. Once the story got enough confidence to shorthand the characters' personalities, it tended to get lost up its own ass with earth-shaking events that are actually kind of blandly predictable.
I think, by virtue of being the second game in the series, Half-Minute Hero: The Second Coming simply could not be as audacious or inventive as its predecessor. Which is entirely to be expected, but unfortunately, it failed to do what the best video game sequels usually manage to do - it did not refine or expand the central idea that made the first game promising enough to develop a sequel. In the original Half-Minute Hero, the time-rewinding and fast-leveling mechanics were the vehicle for an outrageous hypothetical - what if you could cram an entire jrpg into 30 seconds? In the sequel, they're just how things are done. It's fun, because the quests still retain that time-management puzzle quality that makes them a blast to try and solve, but it's completely lost its capacity to surprise and delight.
I enjoyed myself immensely playing this game. I didn't just resolve to get to the end of the story missions and quit. I did a lot of grinding, exploring the optional sidequests and hidden dungeons (though the so-called "global dungeons" were not a timer and thus lacked the game's single biggest source of fun). I must have spent an hour at the casino, pulling the slot machine lever hundreds of times to get enough tokens for the ultimate sword. If I wasn't especially impressed with the game, neither was I disappointed with it. It was a scaled-down, simplified jrpg with a familiar plot and appealing cast of characters. It didn't need to be much more than that to earn a permanent place in my affections, even if I never do play it again.