Definitely harder than the first three.

[Hemiak]

I have one more trophy to plat this game, but I ran out of time last night. I just wanted to let people know this version is quite a bit harder than either of the previous 2 games on nightmare(adventure doesn't have a nightmare setting). In the others, enemies did more damage and took more damage but nothing else changed. In Trap Team the boss fights get quite a bit more difficult. Each boss has one or more abilities that now come much faster and much closer together. I beat nightmare on both Giants and Swap Force with maybe 2-3 figures each. I went through almost 10 characters on 2 bosses and closer to 20 against Kaos. Most of my characters are either level 20 or in the mid teens.

Using Threat Pack is very helpful as you don't need to aim and can just hit his attack while focusing on dodging, but it was still an extremely painful battle. Good luck and fair warning.

[IceKnight_13]

It depends really. If you have the Kaos trap from when you beat him on hard to unlock nightmare, it really is a very easy fight. Simply rotate between Magic and Undead attack and kill Kaos without losing a single skylander.

[Akyix]

I think all of the other trophies are more simple but the nightmare is quite hard (i played this before on XBOX)