Took me about 8-9 hours to plat.

I enjoyed it a lot more than playing as Delsin in SS. It shows that Delsin is more about versatility, than mastery of the powers he takes.
I agree, i liked playing as Fetch more. Maybe it was because i only had to focus on one power. Sometimes the simpler things are better. I really wish this game had a longer story or more things to collect or do in free roam. I almost didnt get it because Kotaku review said i shouldnt play this game. But im glad i took the chance. It was a fun, but short game, and a pretty easy and not time consuming platinum trophy.
I got the platinum last night for First Light and i would recommend to wait and do the challenges after you beat the game. I didnt have much trouble with the survival ones, i think i have around 1,500,000 points for the alpha and beta survivals. It was the Beta Rescue that was pretty hard. I actually got over 500,000 points from a neon singularity right before my 5th hostage died. But after i beat all those i still needed about 100,000 to get the 10,000,000 points challenge. Then all i had to do was upgrade the rest of my powers for the platinum.
I wouldnt say its that hard, you just have to know what to do. Look for ammo boxes to blow up enemies, get those flying helicopters for special powers like infinite melee kills, power bolts, invulnerability. I think my main strategy was to shoot missiles a lot, find a recharge and do it again. Try to stay on the side of the arena where there are the least enemies, high places help too, or even the bottom floor you can find cover in if you dont usually spend time down there. And always save your neon singularity when you are in trouble, or there are too many enemies all over the damn place.