I remember the first one!
This was pretty good, and at least a visual improvement over the other one. I see enemy variation, which is good, and we can actually see the path, also good. Planes are a bad idea, or at the very least, against the normal idea of a tower defense game. Your cannon towers are still under cost compared to the enemies; I can't tell how much effect my rocket tower is having because of the cannon tower's ownage. The same problem is present with the final level of a tower--the description remains exactly the same as for the penultimate level. Looks improved over the first one, but still in need of work. I look forward to the next one, friend! :)