Ttyjukl

This is a long shot but I'm really in need of help for this because it was an amazing book. It was either a kid's or YA book. A guess from what year it was published would be 90s-mid 2000s, as I read it around 2008-2011.

• The book cover was in first person view, with the main character holding a weapon, and was a 3D rendered image inside a dungeon or cave (that was very reminiscent of early 90s CGI animation), though there may be variants.


• It would have been set around when computer games were mainstream (maybe around the same time as when it might've been published) It's about a teenage boy who is bored at home, so he looks through an old family computer to play a game and finds one that he has never seen before. When he plays it he gets transported into the game which is a fantasy-medieval setting.


• All that I can remember about the game and story is that the main character is on a quest, he rides horses a lot, (to the point where he can ride horses perfectly in real life), at one point he eats food at an ingame tavern/restaurant? and he tosses the ingame coin currency at the server because he's in a hurry, (don't know why I remember that bit specifically haha), and he meets a gnome/dwarf character who is helping him on his journey, who has a home in an ingame mountain, and that time goes faster in the game. (For example, if he spent 5 minutes in the real world, 3 in-game days would have passed)


• Sometimes as he's playing something stops him from being able the play the game for a few weeks, maybe a concerned parent because he's playing too much or there's a family vacation. I remember during the time when he's not playing the game he's on a farm and knew how to ride the horses there.


• 
  

  There was a character in the real world who was the main character's sibling, relative or friend. They were like a rival and was also very whiny (to some extent). They were on the farm as well with him and questioned how the main character knew how to ride a horse when he had never done it in real life.

  
  
  

  This is all I can remember but if you need more specific information I can try and answer.
  It is definitely not Space Demons or Demons Don't Dream.
  If anyone knows anything remotely similar please mention it, I would really appreciate it. Thank you!!

  
  

I think that you might be looking for Eden's Gate

Although I have not read this title, the cover matches closely to your description.

Here is the synopsis from Amazon:

When Gunnar Long is transported into the first fully-immersive virtual
MMORPG, he finds himself in a new world filled with magic, mystery and
adventure.

No more 9-to-5 job. No more studio apartment. No more reality TV.

Finally, he's in a place where he can call home, a place with people
he can call friends.

But as more people want to trade their real world lives to get inside
Eden's Gate, the government of the outside world wants the "game" shut
down at all costs.

Gunnar must learn to survive, grow in power and find a way to send a
message back to his old home.

"We're fine. We're alive. Eden's Gate is real."

Does this cover look familiar? Based on the accepted answer to this question
this is the cover of the 2nd book of the Finn's Quest series by Eirlys Hunter, Coldkeep Castle (2001).

The publication date (2001) and the subject matter (a computer game with real-world effects) both match. See the answer to the other question for more details.