well, yeah it's WIP and basic. Keep up the good work nonetheless.
Since mission design is difficult to judge in a video, I will instead comment on the lack of an interesting background. If you want, check the official TBP website, there are actually some nicer backgrounds to download.
The scenario might be a bit problematic, since it's difficult to get dialogue. On the other hand, you could go a more arcade way with this mission, since you are not supposed to survive anyway right
Come up with a good scoring system (combos, survival time bonus when close to the convoy, whatever) and don't forget to make it obvious to the player by using messages.