Video Lags After Rendering is complete!

Hey guys I'm making a Top 3 Horror Games 2013 Edition for my channel, and I wanted to put in this scary clip of gameplay. It's fine in the RAM preview, however after being rendered and viewed it's like a slideshow?? It's an MP4 file and I render in MP4 also in MainConcept AAC/AVC.

Can someone give me some tips on how to get this fixed? I'm pretty sure it's just me and my lack of knowledge when using an output.

I selected MP4 because it gives fast uploads on Youtube.