The Witcher.... Where to begin? This is indeed a huge game. There are so many things you can do in this game; hundreds of quests to be done; thousands of characters to talk to; twists in the plot; factions to choose from.
The Witcher is the ultimate RPG. You have so many monsters to slay.
The downfall may be the combat system. At first, it may seem awkward but you'll get used to it.
You can upgrade your swords, styles of fighting and magical items.