Beat all maps and tiers as the mercenary. I started off playing through the campaign until starting tier 4. Then I went back to complete a few bonus objectives and improve 1 stars in earlier tiers as I was completing each map on tier 4. Going from 2 stars to 3 only awards 1 trap point so I did not consider it worth my time. The final 3 maps in tier 4 were extremely difficult. Took about a dozen tries on Necropolis to barely manage a 2 star. The last 2 maps I had to watch a video walkthrough and learned I could respec traps and skills. I didn't actually need to respec for Wounded Crag but I was doing the opposite strategy of trying to kill the armored with traps and personally killing the flyers. The final level was absolutely crazy but was all about monster summons and winter queens. I got 2 stars on 20 stages and 3 stars the remaining 32. I then did the bonus scenario maps. They were a joke compared, but I was not able to last more than a couple minutes in Armory because it is for 3+ players. I did every map on scenario with 2 maxed out difficulty modifiers for potions and rage gain; don't really need that anyway. I beat the 1st map scenario with fully maxed out difficulty, which was only possible because all lanes converge on a choke point. I did the 1st map endless and made it to wave 30, gaining about 30 levels ups. I did the 2nd map to wave 20 before quitting of boredom and did not want to play any more endless.

Ended at level 90. I used the rulsalka pet for damage on frozen enemies. I have the entire combat tree maxed out except for only 1 point in murderous blow, which inflicts physical vulnerability. I focused on personal combat ability and survival while completely ignoring the trap boosts. I did use the trap boost free point until I unlocked bash, and the free point in touch of death until I respecced near the end and got the fire attack. Frost ring was the best skill with constant area damage and was good vs armor. I used chain snare a lot to pull enemies into the frost, towards traps or just for a ranged attack. Ghastly shape I used more as a dash to get around quicker and only used it on enemies in the most desperate situations. Bash hit extremely hard and I used it to wreck bosses, giants and armored, but it was costly on rage. Fire strike is interesting as a ranged area attack but is a little awkward to aim. The rest of my points are in reset time for mechanical traps, starting essence, and ice snd physical vulnerability. If I was max level I would put the points into reducing trap costs or improving summons.

I took a balanced approach towards upgrading traps, very early on zeroing in on the gun turret and poison geyser. Here is my final setup after beating those extreme levels.

Lava grill: 13 ranks in damage and the 3 buildable upgrades maxed. This was my go to hoard killer and most commonly used mystical ground trap. I never did get around to building 5 fully maxed out of these to unlock the portal glyph, but then I would refund the disorient upgrade because I don't think it is useful.

Icicle field: 13 ranks in damage and the slow upgrade maxed. I put these near the base to give me more time to react, and in combos with other traps to increase the time enemies were exposed.

Stasis: no points. Only ever used it once in a scenario.

Abyss crater: no points. Used a couple times early on since it did better damage vs giants than the lava, but the ice does better with upgrades. I could see this trap being key to high wave endless.

Acid geyser: 13 ranks in damage. 10 in reset time. I love this trap. I like to have 1 to fall back on near the base to take advantage of its physical vulnerability for my own attacks. I also put them before physical damage traps for good combo.

Spear trap: 13 ranks in damage. I put these further away from the base and in spots that the geyser would not get a combo.

Essence trap: only used a few times in spots that are not on the enemy path or where I knew I would make a stand.

Spring trap: occasionally used to delay enemies to combo with damage traps, especially close to the base.

Tick mine: never used. I don't like the sound of it at all with random chance of even doing anything and only doing damage to other enemies when the target dies from something else. Pass.

Lightning pillar: 13 ranks in damage and reset time. My go to anti armor, so I want it to be effective. I did not like the upgrades though so did not put points there.

Frost pillar: 13 ranks in both and upgrades fully maxed. This is my favorite overall trap and I love the way it can almost defend a lane by itself, even cycling between multiple targets to keep them frozen. I always put maxed out ones near my base.

Phoenix pillar: 13 ranked in damage. My go to anti hoard when there are not mystic ground slots, or to supplement. I like putting them near the enemy spawners so they get a fireball to the face first thing. I also like how they can knock enemies down for a little delay.

Entropic pillar: never used. I hardly ever needed to use healing potions so I did not see the point of bonus healing. I guess it could be handy for healing those giant golems or a monster cage.

Olympus pillar: 13 ranks in damage and reset time. Upgrades fully maxed except only 2 ranks in area. I love this trap but they need the upgrade that reduces strike delay in order to be useful. This makes them a bit more of an investment. They also have great range. I tend to use quite a few of them, especially putting them in out of the way and central locations to make use of the range.

Gun sentry: 13 ranks in damage, 7 in range. Upgrades maxed except only 1 point in area. Just like the frost pillar this is one of my favorites. I put them near the base fully upgraded with just a little area effect to spread that slow effect, and elsewhere for giants.

Razor launcher: 13 ranks in damage, 10 in reset time. Damage upgrade maxed. My other go to anti armor. I make sure to set them up where armor will go, and like to put them far from the base, especially at choke points where they can shoot perpendicular.

Blast furnace: I never unlocked this until late and only used a couple times.

Volt coil: 13 ranks in damage, 1 in reset time. A good point blank area damage for when the trap slot is right next to the enemy path, especially at a crossroads and when all kinds of enemies are present.

Cannon sentry: longest range of mechanical tower traps so I put them in out of the way places. Not a significant part of my strategy.

Monster cage: this trap is great when fully maxed out but sucks with only the permanent upgrades. So I don't have any points in this. You either don't need this trap at all, or need it fully maxed for a few specific levels.

Reanimator pit: never used. I don't like how the undead only last a limited time and only work for dead enemies.

Archer post: I used these in the levels with flyers that fly over voids and a few times when the trap was not directly on the enemy path. Their range is not good though and they are somewhat lacking in effectiveness. I used to have points spent here so I am not talking about the base 0 point trap.

Suicide swarm: 13 ranks in damage. My go to summon. I like the fire and forget nature and the impressive distance the little guys will go. Just for bonus damage here and there, and they work incredibly well against the annoying fast flyers.

Winter queen: 7 ranks in damage. Great trap if you can keep her from taking damage. I generally prefer the suicide swarm but there are a few places where she can use her good range and be safe.

Equipment:

Green rustwalker armor level 47. Fully upgraded. Has + hp, + armor, + rage on kill, + damage vs slowed, + rage and a ton of resistances.

Purple dread officer armor level 63. I can't afford to upgrade it so it is not better.

Purple sorrow polearm level 57. 6 upgrades. Has + weapon damage, ice damage, poison damage, + damage vs hoard, + rage, hp leech, physical damage, + damage of fire skills and ice resist.

Purple vandal helm level 90. Fully upgraded. Has + hp, + armor, + damage vs stunned, + rage, item find, crit chance and a ton of resistances.

Purple lone wolf belt level 90. 3 upgrades. Has lightning damage, crit damage, fire damage, fire resist, + hp and hp leech.

Purple spider queen's curse amulet level 58. 2 upgrades. Has poison damage, damage vs poisoned, physical resist, crit damage, and hp.

Purple wraithbone ring level 54. 9 upgrades. Has + damage of physical skills, crit damage, damage vs giants, + damage of lightning skills (mercenary does not have any), physical damage (5 times!), hp, hp leech, resist all and spell cooldown.

Yellow rune level 42: 11% discount, + damage of fire and physical traps

Yellow rune level 90: 14% discount, + damage of ice traps, + cannon sentry.

Yellow rune level 90: 14% discount, + damage of ice traps, + razor launcher.

And a ton of other runes.

Overall I enjoyed this game. 7.3/10