Instead of using roman letters, learn Japanese the way Japanese learn it: learn Hiragana directly.
Research shows that having fun increases your learning. In other words, playing a game doesn't just increase your motivation, it is also a scientifically proven method for learning faster and better. Just think about it: are you more likely to remember exciting things or boring things? Personally, we try to forget the boring things!
Frustrated about having to concentrate to recognize words? Want to increase your reading speed? Users report that their reading speed dramatically increased after using Lingoracer.