As far as i could follow it, by reaching an amount of kanji you get a new "rank" (i.e. Hello Kitty in your picutre, alright). So if you answer to 1000 flashcards correctly, you will automatically have 1000 experience points (let's call them EXP) and you gain a new character - which is fantastic. It does seem so childish at the moment, but when it comes to more complex stuff like getting items etc. you can turn Anki into a nice SRS-Game (amusing for me at least, it seems to be more like playing and not drilling vocabularies). Keep it up and: any German translation available? 
Concerning the ranking system: keep it smaller, like 250 Kanjis (for slow users/learners especially helpful) being more userfriendly finally.
Concerning items - if you have time programming them why not, can be a nice additional part of the game you are creating right now.
Good luck, greets from northern germany,
T.
Concerning the ranking system: keep it smaller, like 250 Kanjis (for slow users/learners especially helpful) being more userfriendly finally.
Concerning items - if you have time programming them why not, can be a nice additional part of the game you are creating right now.
Good luck, greets from northern germany,
T.