These days, I'm totally really into this the computer game named '창세기전3(Chang-Se-Gi-Jeon3)'. It came out 16 years ago, when I was in elementary school. It's one of the greatest role-playing games released in Korea. I (remember that I used to sneak/ I have vivid memories of sneaking) into the (computer?) room in the middle of the night to play the game without my parents knowing. which explains how much I loved it. I'm so happy when I play it because it brings me back to my childhood. Today, they don't produce as many PC games anymore as they did in the past. However, there are some great games that used to be very popular back in the days including the one I'm playing.

Notes: 

1. "Totally into" - This is a colloquial phrase usually used by teenage girls

2. "This game called..."  - I wouldn't use this here, because the Game is not 'called' "창세기전3", it 'is' 창세기전3.  You should usually use "a ______ called ______" when it is a nickname, or an abbreviation. Usually.

3. "I have vivid memories of sneaking" - This is a more evocative way of saying "I remember that".

4. "Which explains how much I loved it".  This just isn't necessary.

5. "Anymore" and "as they used to..." mean the same thing, so you should only put one of them.

6. "including the one I'm playing." - This is awkward phrasing

Its been a long time. :P