There's a tree-cave with two two-bush rows in front of it. Inside are 3 indestructible mushrooms and 5 bushes along with a moving rock. It is possible to trap yourself on the outside of the mushrooms. Wtf?
Dear spikes: Go f*** yourself
Dear Throwing-enemies-that-can-infinite-combo-you-in-a-corner: Go f*** yourself
Dear Death-traps in a FREAKING Ruby room: Go F*** Yourself
Dear wall-climbing spikey things: GO F*** YOURSELF
Dear Swingy-Hammer things: GO... F***... YOURSELF
Dear Rainbow/double bombs: ... will you marry me?
Dear Desert-5: ... f*** you...
... I still beat it, though after the first two levels, I really didn't even use my sword... and it was the only thing I upgraded. One actual cheap thing was that occasionally, the checkpoints respawned me IN a deathtrap, so 1 death became 4.
So, I get the feeling I'll never three-star the levels where enemies spawn from both sides. I simply make two center columns of gauss cannons, maybe one for healing, and maybe one for drones, then spam the other blocks as buffers towards the sides. Lose a few hundred useless towers, save the 10 I really care about.
I'm just going to say this now: Level 14 is utter bullshit. Until you level up to the point where you can easily kill four enemies without dying, you don't have much of a chance of keeping control over 2 flags. You need to grind a medic to lvl 30 or so to stand a chance, or possibly a good tank with the luck of having the enemy spawn within sight distance.
Simple way to get the 3000 kill achievement: Get a lightbringer, max it out, add enough turrets to hold back the infected fion drones, and go to that level. Alt-tabbing is optional.
Something weird keeps happening. 4 galaxy turrets will not fire at the lvl 1 boss if they're off screen. Only the base's plasma cannons hit him, though he's easily within range.
... So, I've maxed homing rockets on the final ship with 50% damage addons, and I'm typing here while my plane sits in survival mode. This seems a little OP for farming XD
So, uhhh 8 tankers with the freeze gun (Obtained from the P-Body level) will basically freeze-lock everything. Just be prepared to do something else for 20 min.