Ranged units are ridiculously OP, I beat every mission on hard without breaking a sweat, just by massing ranged attackers, they kill stuff before it hits them and get huge rankups, and pwn everything.
I managed to beat lvl 9, 2 lasers at entrances, 6 lightnings placed 3 on each half of the map, in the places where they can hit the most track, upgrade their range a bit so they can cover an extra horizontal part, place slow traps adjacent too and in between 2 corners, so that they are just touching the corners on each side, enemies will slow longer than on a straight stretch of ground. All cash was spent on upgrading lightnings and replacing worn out traps.
Rather than making the game easier my advice to the dev, would be to add a difficulty selector, I too was frustrated by the difficulty at first, but I know the dev must have been able to beat it during testing somehow, and I've been unable to tear myself away from trying to figure out how, part of me just enjoys the challenge.
melee weapons are still broken, did not know there was more than 4 areas, only needed 4 to max upgrades on everything, upgrading to lvl 5 gives the item but doesn't show on the upgrade screen, rocket explosions can kill enemies that walk into them minutes after the explosion animation finishes (it's like placing invisible land mines). For the guy that asked about the money rewards, you must pick up the cash the boss drops to get the big money, which means staying close to him when you kill him, holding down the 'a' button and randomly moving up and down should work.
for the dev: there seems to be a strange bug where enemy meshes will disappear and leave only a shadow, on rare occasions the laser tower mesh will flip upside down, upon completing the game it will always say that lasers were unlocked, even if it was tesla coils, or if I had both already.
For the newbies: Machine gun is the most useful tower, since cannons only hit ground and flamers have targeting troubles on spiders and devil girls.
Use bells to stun vampires so you can shoot them a bunch before they enter bat form.
Build towers and walls in a spiral formation, monsters you kill at the last second with first person shooting don't give you any gold.
I managed to beat easy with 0 leaks using only machine guns and a few bells.
Since the dev left a comment saying he made it easier it may no longer matter, but I'll share my strategy for lvl 45 anyways. I started off trying to take as many barracks as possible, then when he is about to start researching poison I sent everything I have to steal his lab. you can't freeze or poison his main barracks at top right, so what you want to do is steal his forts, in particular, take the two at the top right, right next to his main barracks where he keeps sending out troops. This way every time he sends another wave they get shot up by his own forts. This relieves a lot of the pressure on you in other areas of the map and robs him of his main advantage, troop spawning rate. His AI doesn't seem to make good use of the extra barracks' he takes, he just keeps spawning at top right next to those 2 forts. I was able to use the lab to slowly steal every fort on the map and eventually win.
For the dev: as others have mentioned the bank tower on page 2 disappears between levels (haven't checked the others)
also during a level I hit the buy max upgrades button for the right upgrade tree on one of the sniper units and somehow ended up with -3 cash :P
Took me a while to realize the health meter was actually the launch power meter and that letting it go to 0 and come back up wouldn't kill me. Can't help but wonder if some of the people complaining about it taking too long to earn money are making the same mistake.
At first I was annoyed that it couldn't understand my question about how the war started, but in the end it made sense with the story. As a programmer I'm intrigued at the technical aspect of the language parser, just a few more years and we can have androids :P
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