Slime forest is a free game, although you can pay for additional functionality, which can be found at www.lrnj.com .
I first discovered this game about ten years ago, when I was first trying to learn Japanese. I was still at the phase of learning Hiragana and Katakana. I was using flashcards and getting frustrated because I couldn’t seem to remember all of them, and the ones I did remember would be forgotten within a few days.
Then someone at the Japanese club (yes, my friends and I founded a Japanese club at my high school) said, “Oh yeah, try lrnj it’s fun!”
I mainly played just to learn the Japanese characters, but you could play this just like a regular rpg game. It was very addicting! I learned the characters very quickly, it was easy to motivate myself to type faster and not get killed by a stupid slime! Ten years ago, I was convinced that this was the future of language learning. There would soon be other rpgs that were basically this, but a different theme. Perhaps in other languages as well.
I only stopped playing this, after I learned hiragana and katakana because the slime forest game only tested on the English meaning of kanji characters. I thought it would be better to learn Kanji with pronunciation AND meaning than just one or the other.
In case you are wondering what the premise of the game is: You are a potato farmer that has to kill slimes with a hoe. You then are given a quest by the king to save his daughter. You have to raise money to buy a boat to go where she was taken, and you do that by killing slimes. Each slime has a character on its body, and you have to type its pronunciation. If you get it wrong, it jumps up and down and gives you the correct answer, but then it takes more tries to ‘kill’ it and get the reward.
Every once in a while, I’ll download this game again on different computers. It’s still fun even though I don’t really need it any more.