These are some of the post ideas for your gaming blog. You can always think of more.
1. Latest game launches across all platforms, be it Android, Windows, Xbox, Playstation etc.
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2. Latest game reviews.
3. Game playing tips.
4. Secret unlocks and cheats.
5. Gaming console launches and reviews.
6. Top games across different genres (E.g: Adventure, Strategy, Racing etc)
7. Top games across different platforms. (E.g: Top 20 Android Games)
8. Articles revisiting games of yesteryear's.
9. Historical perspective on game development.
10. Upcoming game launches and previews.
11. Announcement and coverage of gaming tournaments.
12. Gaming Laptops and accessories. [Launches, reviews, comparisons, Top 10 lists etc]
13. Coverage of Gamers' events.
14. General news surrounding the exciting world of gaming.
15. Game developer interviews. [This is a relatively unexplored area]
16. Game playing videos - videos that feature you playing the latest games. Cross post on YouTube to maximise viewership.
17. Game development cycle.
18. How to guides on becoming a game developer.
Your blog can also feature a forum where gaming enthusiasts can discuss everything related to the world of gaming. You might also be interested in organising your own Gamers' Meet through your blog.