A lot more time than what? A lot more time then other people? For most people the game takes quite awhile to load, at least via browser. The game was primarily built for mobile, and it loads relatively fast there. Also it doesn't help that a lot of browsers treat unity as it would flash, and try to run a 3d game on a system made for 2d.
Japanese is the 9th most common language after, Mandarin, Spanish, English, Hindi, Arabic, Portuguese, Bengali, and Russian. That is hardly considered dead, and considering Japan is the tech hub of the world Japanese is one of the more important languages to know.
I understand that you might want that to spice things up a bit, but Adventure Mode is mostly targeted at new learners who don't have much prior knowledge of kana (memorizing them all is difficult enough already!), and the later stages do get quite fast. But if you are into a "hard mode", feel free to test yourself in Free Play! The "impossible" difficulty of Free Play is faster than the hardest stages of Adventure Mode, and things also get faster over time.
It's kinda funny to see people complain about PvP without reading previous comments. PvP 1 is broken PvP 2 and Duel work. Its been like that for years at this point.
While I agree it is a bit discouraging I am still not sure what this game would be like without large timers. Three days of the week I got nothing better to do but stay home and play games, while the other days I hardly get on for an hour. Even so I have already gotten 1 champ and 7 master, and am half way done with the campaign, but I'm not trying to brag, I'm here to prove a point.
The game passes fairly quickly for people with the time, and as a hard core flash gamer it does just that. If the timers we less then game would not be playable for an extended period of time, and they don't want someone like me charging through the entire campaign in a short period of time and then being hit in the face with a wall at the end. Once the end hits all one can do is sit around waiting for new content or dungeons to reset, what kind of player would enjoy that, and how does a game make money on that? Players will always be able to progress in the game faster then the developers can make the game, and so there has to be some way to prolong the content. Other games in this field may do that by missions re-rolling, but that provides similar problems.
They are probity trying to think of a way to make to replay whilst not allowing players with a ton of time to get infinity good. Even when replay happened i bet it will be limited, like you can replay each mission once per day.
 "Lionheart Tactics"){kind=icon}
 "Elements"){kind=icon}
 "Kana Warrior / かなウォリアー"){kind=icon}
 "Akaneiro"){kind=icon}
I understand that you might want that to spice things up a bit, but Adventure Mode is mostly targeted at new learners who don't have much prior knowledge of kana (memorizing them all is difficult enough already!), and the later stages do get quite fast. But if you are into a "hard mode", feel free to test yourself in Free Play! The "impossible" difficulty of Free Play is faster than the hardest stages of Adventure Mode, and things also get faster over time.