This game is very addicting, I started in 2005 and I still can't leave it, so don't start playing if you get addicted easily. People say if someone starts playing this game, a person never quits, he returns to this game again and again.
This is one of a few games which I have played for my whole life, so I gave it 10. Also, Runescape 3 Html has one of the best graphics I've ever seen... I can play BF4 on 20fps, but I get only 7 Fps on Rs3. You need an extremely good graphics card to play Html version of the game.
Also this game takes a lot of time to finish. I got all skills to max level in 8-9 years of playing.
In conclusion I would like to say that you should try this game, but don't get addicted. Usually that happens in like a month or two. Also try not buying a lot of gold, or cosmetic items, because if you do, then this game will take too much money..