Although the game is only in Japanese, there seems to be less text to go through, and I had no problem playing even if I don't understand the plot (the same reason you can finish most Japanese-only RPGs, I suppose). The game seems less story-oriented than Akuji, which means more action, making it much easier for non-Japanese to complete. Controls are quite intuitive too: you use the arrow keys to move, Z to swing your sword, use items, or interact with objects/people, X to use special "spirit power," and C to switch between spirit powers (as you collect them through the game). Press Q to save, F1 to see your inventory, and ESC to see in-game options. If you liked Akuji or Zelda-style action/RPG hybrids in general, Guardian of Paradise is yet another polished and fun freeware gem to keep you entertained for hours. Highly recommended!

Note: The game seems to be unavailable at the moment. If you have a copy, please contact some abandonware site[s] and see if they could host it.