I haven't fought him in new game plus yet but I did have a lot of trouble fighting him the first time.
For the flying attack, the only advice I can give is that if you're close to him while he's in the air you have to run to be underneath or behind him during the attack. If you're at least medium distance away you can try to run out of range. The flame attack has a long range taking up at least a third to half the arena.
I found that being medium distance away is what killed me more often than not. Too often you get trapped.
The first year I get xbox live I use my credit card. From then on I buy the year card on sale. A year goes by and it tries to auto-renew even though I still have 9 months of service. It tries renewing through on an old credit card that has expired and I never updated that particular card on live. It does this once a month a couple of more times. I only know this is happening via email showing that activity.
Then I start getting emails they will lock my account due to non-payment. I still have 7 months of service active! Anyway I contact their online support and do a live chat. They get it squared away but had to give me my 7 months back by using monthly codes. I hope the system is getting less backwards over time.
I saw it yesterday and I think it's great. It was a lot of fun watching the endless grind of trying again. It was kind of like the immediate retry in Super Meat Boy or Super Time Force. For example in one scene he gets hit by a truck and then you see him try it again.
I'm going to talk about the ending a bit.
Although I'm not sure if the ending's event really line up correct. He wakes up, but the news says the explosion of the omega happened the day before. So with the explosion in the day after, with him getting the "time blood" he makes the omega explode retroactively? I suppose with him stealing it's power, the aliens couldn't stop some event beforehand that leads to their destruction.
Also for those that say the repeating day structure is overused, can you name more movies. Off the top of my head I can only think of Groundhog Day and Source Code. I suppose a lot of time travel movies could count, like Primer, Time Crimes, and maybe that one scene in Back to the Future 2?