This isn't a full review of Resistance Burning Skies as I haven't finished the campaign or tried the online yet. But I am a few levels into the single player now and feel its enough for a good review.
Anyway let me start by saying I am a big PS3 Resistance fan so I may be a bit biased but honestly I actually really enjoyed Resistance BS! - and do not understand the hate.
For starters I see a lot of reviews complaining particularly about the touch screen controls. But they don't bother me as I have seen much worse on iPad! (yet those iPad games somehow manage to get glowing reviews?!) yes dragging and dropping your grenades is annoying but you don't need to go through all that you just need to aim above your enemy and tap the grenade icon once to throw a grenade accurately at your target! Other than that I've only so far seen the touch screen involved with using your weapons secondary fire which is occasionally frustrating in the heat of battle (when spreading 2 fingers out to throw out a shield yes that does slow down the action a bit) but its a one time thing. Personally I found doing the puzzles in Uncharted with touch screen more irritating!.
Moving onto the second big complaint: the graphics. I don't know what game the critics have been playing but I have yet to see my vita struggle in the heat of battle. Yes the environments are not as pretty as Uncharted (it's altogether a bit too grey I reckon) but the explosions and fire fights hold up really well!.
Although I haven't yet played the online side of the game I am looking forward to giving its weapons as good go as I've been really impressed with them in the SP Campaign! There's a wonderful variation And you always seem to be unlocking more! And when you get a new weapon you'll be desperate to see what new secondary fire the weapon holds! From crossbows napalm to the auger and it's shield deployment every weapon holds and exciting new secondary fire mode!
One of the other main aspects of the Resistance series has always been the boss battles and Burning Skies is no different! Don't worry I won't spoil anything for you but you can be sure there's some big battles to look forward to!
Finally in terms of length I'd guess Burning Skies has a good sized campaign! Longer than you're average shooter anyway ;) I suppose the lack of Uncharted-like collectables hunting means the single player has little replay value but then you've always got the online and it's unlock system (I keep hearing so much about!).
To sum up my review: Resistance Burning Skies isn't going to set the shooter genre alight but it is a revelation for handheld gaming and shows good signs for things to come!
Resistance BS = 8.5 / 10