I've almost finished the latest update for Hex Defense (which adds all levels upto 35). I beat all levels on Normal and all but one on hard, so I know the basics well. With beating I mean advancing in the levels waves far enough to get it to say 'next level' instead of 'retry level', this is somewhere around level 22.
How can I beat level 32 on hard difficulty?
Level 32 is call Border Patrol and has the creep walking on the sides of the screens, where you are not allowed to place any towers. The middles has a big field where you can place the towers. The normal strategy of starting with a laser tower doesn't work (because there are no places where you can align to hit several creeps with one shot). On easy I managed to eventually place on decently upgraded rocket tower in the middle (that can hit both sides). On hard I can't get past lvl4.