I finished the first loop of Jumping Flash 2 (both games have a thing where you basically have to beat the game twice with level layout and difficulty tweaks on the second loop)... but then I lost my save file somehow. I don't particularly feel like playing through the first loop of the game again so soon after beating it, so I guess that's that for now.
https://www.youtube.com/watch?v=o7ViNlDj604
Jumping Flash 2 improved on the engine a lot. There's a greater draw distance, inclines actually effect your POV to make it look like you are tilting, the enemy AI is smarter, and the HUD is a lot better and more helpful than the first game. There's also some really nice set pieces in the stages since they are able to focus a lot more on height than the first game did. And I really liked some of the exploration that was introduced that the first game simply couldn't handle doing.
But... it's really obvious to see that they basically took the first game, updated the engine, and put a new level pack over top of the old levels. The underground levels in the first game correspond with where interior levels can be found in the second game. The final world is really thematically identical to the final world in the first game. The final boss arena and even the fight itself are almost copies of the ones from the first game even if they are a bit more difficult. I know they did a lot of this to cut development time and costs, but it's still pretty disappointing that it isn't too hard to notice this stuff, especially with the final boss. 
The levels themselves are hit or miss for me. While it's great that they introduced a lot more exploration and this led me to like a few of the levels more than some levels in the first game, they also decided to introduce a lot more near pixel perfect jumps. There are so many one square wide platforms in this game. It's not hard by any means, but it is super tedious, especially if you are trying to go fast. The music was still pretty nice, but I didn't find it quite as catchy as the music from the first game.
This game introduced a lot more voice acting and the English VA cast is... uh... hit or miss. Baron Aloha sounds okay, but the other villain in the game sounds really... off and makes groan inducing jokes that are worse than any puns I could come up with. There is an announcer guy that shows in the intro, the ending, and carries over to the title screen and I just can't help but chuckle every time I hear him say "Jumping Flash 2! <insert game subtitle here>" since he sounds like an old Saturday morning cartoon announcer.
They also introduced navigation AIs that have their own voices instead of what I kinda assumed was Robbit speaking in the first game (not that he said much). The voice you are stuck with for the majority of the game sounds like something out of a Monday morning educational cartoon and doesn't really fit with the atmosphere. The brief listening I had of the other AI voice on loop 2 sounded like a "I wanna be cool and smooth" voice that's also a bit weird.
So yeah. I did have fun with Jumping Flash 2 and I liked the improvements (especially the draw distance), but at the same time I probably played this too close to the first game and it made it easier for me to notice where they cut the corners. The final boss was a huge disappointment even ignoring that, though. So yeah, I liked the first game better.
Still, this is probably a lot better than the Japan only final game in the series, which I dunno if I plan to try that or not. It's sounded pretty terrible and the one video I watched of it didn't improve that impression.
Edit: Nevermind. Managed to find my save file. I somehow swapped which emulator I was using in the middle of playing since I've got both a stable release of RetroArch and a nightly version of it. Still, that's probably the last I'll yak about Jumping Flash in here unless I subject myself to the final game or I find something that blows me away in loop 2. 
Edited by Nick, 24 August 2015 - 07:42 PM.