Is THIS powerful: The Siege and the Sandfox - Pre Alpha Promo - YouTube
Siege and Sandfox was made with Paper2D in UE4. One of the designers of this game made a talk that you can see here: PIXEL ART in UNREAL - Building a Metroidvania - YouTube
He explains his experience making a 2D pixelart game in Unreal and his conclusions. Hope it helps!