Retro Defense, solving the long distance level

Question

I've been having a good time with Retro Defense until the Long Distance level, where I basically cannot get past 6 or 7 waves (30 is the goal). I did move on a tad further and am also stuck on the Y level. But I'm really flummoxed by this one. Has anyone succeeded, and how'd they do it?

Update
Here's someone's apt description of it, which mimics my experience:

I've figured out you have to use two small reds on the single squares in the middle of the level to start with. If you use one green or two greens you last until about level 5 or as soon as you get some yellows. Small blues don't work. You can get the slow-down turrets, but without turrets being in range at the back this is useless.

Assuming you have two level 10 small reds or a red and a green on the single squares, this will take you to about level 7 to 10 before they're overwhelmed.

The next obvious step is to get some big guns at the back. But, in order to get them in range before the level gets too high for the small turrets to handle, you will need to have been lucky enough to have collected three range boosting upgrades (or power+range combos) and have them in a row at the back all powering up a large red (I've never been that lucky), or you can use a large green (this fails at level 10 as it's too slow).

I've also tried getting large blues on the single squares at the bottom. I managed to get one once, but I died at level 9.

Answer 1

The takeaway I got from a 5 page thread amid discussions of Java SDKs and iPhone vs G1, is that it can be done only when you're lucky, where luck is defined as getting great powerups for the back row and getting almost no red waves until level 15 or so; and even then, very few. Later you want no blue waves.

The other important note is that the end goal setup for past level 15 is to have 2 large and powered up red turrets on each of the 2 back areas, and 2 large blue turrets in the forefront. It's obvious otherwise that you must start with 2 red turrets. Do not use green turrets on this level due to the missile lag.

Here's what living to wave 48 might look like: