If you coded this without an engine I applaud you as the physics system and basic mechanics are solid -- all it is missing is inertia as others have pointed out. I think the game could benefit from having some audio to make it more immersing. If you had time to develop more levels this game could be quite good (its already quite satisfying to complete the limited levels that are in the game).

It's a good game. You fly, you carry boxes. But the lack of sounds was slightly distracting from the dive. also, the lack of inertia in the boxes, it seems to me that adding inertia to the boxes would make the gameplay a little faster. Overall, the game is good, well done

a really fun idea but the player was too slow maybe if you add a music it would help