It is a bit stupid that it is exclusive to Windows Phone and Windows 8, but the reason is straight forward: money. The game does look alright, but even if it were on IPAD I wouldn't get it. I actually had a quick look at the forums on Waypoint and quite a few people were complaining about 343 and Microsoft 'milking' out the franchise, though others argue that the game could be good and it proberly didn't waste much time.
If it was for any other device (android more specifically) I'd get it... Nobody uses windows tablets....
I'm a bit conflicted about it, but first a little clarification on your "but the reason is straight forward: money". It depends on what you mean by money. By making it a windows phone 8/Windows 8 exclusive game Microsoft will make less money on the actual game. Whether that means they'll ship more windows 8 hardware because of it remains to be seen but I'd say the reason is more for advertising Windows 8 as a viable platform than making money on the game (they won't get halo faithful to all buy Windows 8 hardware in mass so it's a bit of an odd move). Back to me being conflicted. While I do think Halo Wars was a good idea at the time for expanding the universe (plus the cutscenes were gorgeous) I don't think Halo Spartan Assault is a good idea. I'd much rather 343i working on more Halo 4 Spartan Ops to better solidify the commitment they promised before release with "multiple seasons". We have the 1 season, great, give us more and make it better. Also, if they have dev time, keep working on fixing the still existing myriad of issues with Halo 4. The recent weapon revamp was good, keep on doing that and keep being active with the community and it is that level of involvement which will get people interested in Halo again instead of leaving in large numbers. I think with Spartan Assault that will be the limit of non regular Halo games that I would "accept" before fully agreeing it's just about milking the label. My guess is the windows 8 exclusivity will only be a temporary thing since they'd be stupid to keep it that way when it could make so much more money on android/iOS
Looks fun but it's unfortunate that they're not using other platforms. It's weird to me that they didn't brand it with Xbox LIVE integration either... I was expecting a smoother integration of LIVE across all Microsoft devices capable of any kind of gaming. It'll be a surprise if this doesn't count towards gamerscore. I mean, it doesn't matter that much, if at all for most people but I really thought they would have tried for it to set some kind of precedent. Mobile games are getting better and better -- I'm surprised Microsoft didn't seize the opportunity in a more "elegant" way. Xbox LIVE integration would at least be somewhat reasonable to use only Microsoft devices. This is all based on the assumption that there will be no LIVE support though. Maybe they'll pull it out of their asses though. I am very conflicted about it too, Pac. It's obviously not for money (or at least right away). It's a marketing strategy that is probably the first in a series of "exclusives" to come. It probably won't work but you gotta take risks.