Microsoft's Halo 4 is a new entry at No.1 in the UK video game chart, but the game's chart position doesn't really tell the whole story.

According to Chart Track, Halo 4 sold slightly more units than last week's Assassin's Creed 3 and has become the 18th biggest SKU launch in terms of week one units. However, the big budget sequel failed to top the week one sales of Halo 3 (15th biggest launch) or Halo: Reach (12th biggest launch).

Assassin's Creed 3 slips to No.2 with a 73 per cent drop off in sales, FIFA 13 is at No.3, Need for Speed: Most Wanted climbs to No.4 and Football Manager 2013 takes fifth place.

Skylanders Giants records a 7 per cent rise in sales and climbs two places to No.6, followed by WWE 13 at No.7, Boderlands 2 at No.8 (up 180 per cent thanks to price cuts), Just Dance 4 at No.9 and Medal of Honor: Warfighter at No.10.

LittleBigPlanet Karting is the week's only other new entry, beginning its life at No.24.

UKIE Games Charts, compiled by GfK Chart-Track, (All Prices) Week 45, 2012

1. HALO 4

2. ASSASSIN'S CREED III

3. FIFA 13

4. NEED FOR SPEED MOST WANTED

5. FOOTBALL MANAGER 2013

6. SKYLANDERS GIANTS

7. WWE '13

8. BORDERLANDS 2

9. JUST DANCE 4

10. MEDAL OF HONOR: WARFIGHTER

11. FORZA HORIZON

12. MOSHI MONSTERS: MOSHLINGS THEME PARK

13. RESIDENT EVIL 6

14. DISHONORED

15. THE ELDER SCROLLS V: SKYRIM

16. PROFESSOR LAYTON AND THE MIRACLE MASK

17. F1 2012

18. NEW SUPER MARIO BROS. 2

19. FORZA MOTORSPORT 4

20. LEGO BATMAN 2: DC SUPER HEROES

Given Halo 4's huge budget, both in terms of production and marketing, failing to beat the week one sales of Halo 3 and Reach will be seen as a massive disappointment. The shrinking UK games market and strong releases vying for attention must, however, be recognised. Halo titles typically launch in September, but Halo 4 went for a November launch and as a result found itself sandwiched between Assassin's Creed 3 and Black Ops 2.

Assassin's Creed 3 proved successful for Ubisoft, but we'll have to wait until next week to find out if Black Ops 2 manages to improve on previous Call of Duty launches.