Actually, those slow-motion effects are part of the game; they serve as combo extenders which allow you to, besides finishing off a single enemy, either change to another turtle and continue the combo, or link into a tag-team attack with two or even all four turtles at once. The fighting system is apparently quite deep and actually seems to play more like a co-op Ninja Gaiden than Batman: Arkham City.
Raph trailer for those who missed it:
Well I noticed the Turtles have two toes now . It looks interesting though, although, from those two trailers, they could diversify their enemies a bit more. All it looked like were Foot Ninjas. Still, I'll withold judgement until it actually comes out.
"You're an enemy of art and I pity your ignorance" - Domingo Montoya
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