Are you looking to add like color grading or background music to this feature, or are you just trying to join multiple files ?
DaVinci Resolve is a powerful, free option. You can drag all your clips into the timeline, right-click, and select "New Compound Clip" to merge them into one manageable unit. g61091.mp4
Use a timeline editor to remove unwanted footage and ensure smooth transitions between scenes. Are you looking to add like color grading
For a player that supports nearly any MP4 variation, the VLC media player is a highly recommended free tool. g61091.mp4