After getting some feedback over the first few weeks, I realized that many people play this kanji driller in the browser with their mobile devices. They found that tapping the slime character to jump was a little hard. 

Now, if you're playing on a touch screen, you tap the sun character to jump. Its hit box is much bigger and the position is more natural for someone holding a mobile device. Also, it's now easier to cycle through the answers - the hit box on the green answer screen is also now much bigger. 

Furthermore, I included a review function at the end of each stage. You can now cycle through all the kanji that were presented in the stage, reviewing their respective kunyomi, onyomi, and English meanings. 

Finally, you can now play levels one and two for free online, instead of just level one. Still, to get the most out of this kanji driller, download the pc desktop executable for full functionality.