I am looking forward to play Kingdom Rush 4 and maybe as many of you I too want some changes or improvements in the battle mechanics.
There are some things that I would like to see changed in Kingdom Rush 4.
1. The way towers choose targets.
At the moment the closest to the exit enemy is hit. This means that a mage tower will prefer to shoot at a spider that is 2 pixels closer to the exit than on a Champion. There is an archer tower in range. Spiders as we all know have high magic resistance and no armor (they will take full damage from arrows).
In another game (Tower Defense King) all towers are smart. All towers in range focus on enemies that will take most damage from them. Mage Towers shoot at enemies with no magic resistance and Archers shoot at enemies with no armor. Further more towers focus on the strongest enemy IF you have build other towers closer to the exit that will take care of the escaping enemies. Cannon towers shoot at swarmed enemies not on single enemies that have escaped from the swarm IF there are other towers further on the path OR single target towers in range (such as arrow or magic tower). The single target towers take care of the escaped enemy while cannons shoot at the swarm.
The same goes for flyers - in Tower Defense King, Realm Defense and other games - archer towers always prefer flyers over walking enemies.
2. In all Kingdom Rush games powerful skills as Instant Kill, Polymorph, Huntes Mark or Druids Curse again target the closest to the exit enemy. As a rule the weakest enemies are the fastes ones, strongest enemies are the slowest ones. These skills are totaly wasted on targets that will be killed in a second or two. Again a smarter approach is needed so you will not regret buying and wasting these skills.
3. Many area skills such as Ward of Disruption are wasted as well because they activate when the first enemy from a larger group enters the range of the tower. Scourgers (the main reason I buy that skill) are slow moving and usualy in groups. Only the one or two of them are affected when the skill is triggered. There are two variants of changing that - either use a counter (1, 3 or 6 enemies are silenced with Ward of Disruption) and if the skill is 2nd or 3d level the tower will silence the first enemy when it enters in range, after 2 seconds another one and so on until the counter hits zero. When the counter is zero than the skills starts to charge again. Or the whole group is silenced when it gets in the center of range. Of course if the towers are made smart (i.e. they are controlled by intelligent beings inside it and are not mechanical toys as of now) the AI will see if only one enemy comes near or a group of enemies that need to be silenced.
4. I think KR 4 needs better distribution among skill levels of damage for some skills. Eldrich Doom kills one enemy and does 80, 180, 260 damage. Why not 90, 180, 270 damage? The main effect of course is insta-kill and this is why the first level is 325 gold and the other two - 185 gold. Kingdom Rush shines among other games because of precision to details and in that tower skill damage per level is random.
5. Better distribution of skills per towers - Arcane Archers is a broken tower to me. It is a Ranged Tower that does physical damage but its skill Burst Arrow does magic damage. You place Ranged tower on a path mostly full of enemies with no armor or with magic resistance. Burst Arrow is wasted on them. I don't get that combination - what was the designer idea behind it. The only map that it is somehow helpful is in the Tainted Pit map where you have many spiders and some Shadow Champions which have high armor and very little choice which towers to place.
Another mix of skills that do not match - Golden Longbows - Instakill and another skills that doubles the damage from all sources. If you can kill it in a single hit why Mark it for double damage? It would be much better if instead of Mark of the Hunter they can slow down some enemy or enemies. Or even better - put them to sleep so they can shoot longer at them in attempts to trigger a killing chance. This is much better sinergy.
And speaking of sinergy between skills - again - the Ward of Disruption feels misplaced on the Wild Magus Tower. Most players buy that skill to block spellcasters. Spellcaster have medium to high magic resistance. SO you have the "smart" choise between two options - either block the caster abilities with Wild Magus Tower but you cant kill them with magic damage OR instead place a Ranged tower but you can't block their abilities (and if it is Arcane Archers you cant hurt them much with Burst Arrows.)
It would be much better combination of skills if Arcane Archers had the Hunters Marks and Ward of Disruption. Golden Longbows - Insta Kill and Sleep Arrows and Wild Magus some other meaningfull and theme-fitting ability.
6. Teleport, Mass Teleporg (Faustus), Twister and Timelapse - in the way it works is a double blade. There are many times when I use Lightning Spell or some AOE hero spell and just a second after triggering it the main target I want to hit is teleported or even worse - a whole group of enemies are phased out of battlefield. Or just a second before a Burning Nut, Burst arrow, Sleeping arrow, Hunters Mark is about to land over an enemy it is teleported back/phased out. Skills and spells that are supposed to help you work against you. The game will have much more sense if all elements of towers work in sinergy. In these cases here it seems that the towers are controlled by good but very stupid guys inside.
7. Maps - I prefer playing KR Original and KR Origins but not Frontiers. In Frontiers - the only good levels are these out of the campaign. All other levels are plain, boring and full of enemies that are simply not interesting or challenging. The only campaign level that offers some challenge in Frontiers is the last one. On the other hand all other non-campaign levels are beatiful, well designed and offer good challenge. KR Original has 99,99% interesting levels, I played over and over again all levels after the first champion (because level 4th towers are available). I was completly bored with the first 14 levels in Frontiers. KR Origins has about 60% interesting campaing levels, the rest is just plain filler. In Origins all levels after the Gryphon point are worth replaying with different heroes and tower combinations. I really hope that the same mistake as in Frontiers will not be repeated in the 4th installment of the game. Most of Frontiers enemies are not even worth of mentioning in terms of skills and there is not much differentiation among them. Most of Frontier maps are poorly designed with linear way of placing towers. At most of Frontier campaign levels (not the undead and sea levels) you dont even need to think which towers to place. A simple example - I have played all of them placing only certain type of towers - Archmage towers or Tribal Axes or Cannons with one or two barraks - guess what - you always win. The only map in Origins where you can do this is fighting Malicia - I have won in different replays with all towers being Arcane Archer, Wild Mages, Druids/Weirdwoods (with only two archer towers) - only the High Mages fail to win against the evil queen. If you can win a map with mostly one type of tower, the map is poorly designed and it doesnt matter what choices you make.