Kingdom Rush 6 Genesis Unlocks & Progression Guide

Progression in Kingdom Rush 6: Genesis is split across several systems, and mixing them together makes it easy to grind the wrong thing.

Stars unlock content. Gems buy permanent upgrades. Heroes earn their own XP. Spells earn XP when cast. Gold only exists inside the current battle.

Once I started treating those as separate resources, the route became much clearer. A locked hero needs more Stars; a weak permanent tech tree needs Gems; an underleveled hero needs combat XP; and a bad tower position cannot be fixed by grinding any of them.

How Campaign Stars Are Awarded

Campaign stages start with 20 lives, and your remaining lives determine the result:

• 18–20 lives: 3 Stars
• 6–17 lives: 2 Stars
• 1–5 lives: 1 Star

The game keeps your best Campaign result, so a messy first victory still moves the story forward. You can return later for the missing Stars without losing anything from the original clear.

Across all 18 campaign stages, that gives a maximum of 54 Campaign Stars.

Challenge victories add another Star each. With five challenge variants across 18 stages, there are 90 additional challenge Stars, for 144 Stars in total.

That is why the 60-Star Impossible requirement and the 100-Star achievement do not require perfecting every possible battle first.

Steam Star Unlock Order

Steam uses Stars for almost the entire roster progression.

The first few unlocks arrive quickly. Gerald and the three starting towers are already available, then Zefira opens at 1 Star, Scholar Mage at 3, Royal Edict at 5 and Dwarven Culverin at 7.

That makes the first several campaign clears more valuable than repeatedly replaying Linirean Castle. Moving forward can add an entirely new damage type or hero before another attempt at an old stage.

Steam and Mobile Do Not Use the Same Unlock Model

This matters most once the Star count reaches the middle of the campaign.

On Steam, the later roster continues unlocking through Stars. On iOS and Android, 18 of those later rewards become in-app purchases instead.

The mobile purchase group includes:

• Malik, Rhodes, Gemina, Ignus, Illiana, Oni, Drakkan and Ashbite;
• Wildcat Huntresses, Alchemist Shack, Ironbark Treant, Arcane Forger and Sentry Watchtower;
• Teleportation Sigil, Gnome’s Shop, Thunder Zapper, Wintersong’s Wrath and Aspect of Sol.

The remaining Star unlocks keep the same requirements, including Impossible at 60 Stars.

So if you are playing on mobile and Malik does not appear after reaching 28 Stars, nothing is wrong with the save. The 28-Star unlock is the Steam progression route.

What About the 24-Star Challenge Unlock?

The Steam progression track opens Blitz, Spell Rush, Hero Party and Classic Rush at 24 Stars. Iron is different: it opens stage by stage after the Campaign version has been cleared.

There is one UI detail worth checking on your own save. I also encountered a Linirean Castle Blitz card displaying “Earn 26 Stars to Unlock.”

If a challenge tab shows a higher requirement than the general mode unlock, follow the number displayed on that stage card before spending time replaying older maps.

Once the modes are available, their rules and build changes are covered in Challenge Modes.

Gems Pay for Permanent Upgrades

Stars do not buy the main permanent upgrade tree.

Genesis uses Gems for those upgrades instead, and Gems are kept even when a battle ends in defeat. The Upgrade room contains four main branches covering the basic tower families and broader combat systems, including the Ultimates used by the normal tower roster.

This separation changes how I spend.

There is no benefit in hoarding Gems simply because Malik, a spell or Impossible is still several Stars away. Spending Gems cannot move that Star requirement backward.

I put permanent upgrades into whatever is already costing lives. If Barracks keep collapsing, troop upgrades have immediate value. If flyers repeatedly survive the ranged line, Marksman improvements matter more than another unrelated branch.

A Star lock and a combat failure are two different problems.

Tower Progression Has Three Layers

A tower can become stronger in three separate ways.

First, the tower itself has to be available. On Steam, most of the later roster is unlocked through Stars.

Second, the Upgrade room improves tower families and unlocks their broader permanent bonuses and Ultimates. Those purchases use Gems.

Third, every individual battle starts its own Gold economy. A tower still has to be built and upgraded through its in-stage tiers, and its Tier IV skills have to be purchased again during that run.

Unlocking Elven Elite Ranger therefore does not make an old stage easier by itself. The loadout still needs enough starting Gold, a useful build point and a purchase order that gets the tower online before the dangerous wave arrives.

For the actual five-tower choices and Tier IV buying decisions, use Best Towers & Tower Tier List.

Heroes Level to 10 and Have Catch-Up XP

Hero levels are independent from Stars after the hero has been unlocked.

Heroes can reach Level 10, and later additions do not always join at Level

1. Bolin starts at Level 2, Connor at Level 3, Malik and several mid-game heroes start at Level 4, while some of the late roster begins at Level 5.

Malik is a good example: on Steam he unlocks at 28 Stars and immediately joins at Level 4.

The game also includes a catch-up system. When a hero begins a battle two or more levels below the expected level for your campaign progress, that hero earns double XP. A hero two or more levels above the expected level earns half XP.

That makes heavy early grinding much less useful than it first appears.

A newly unlocked hero can catch up naturally while you are completing later stages, challenge Stars or achievement cleanup. I only stop to grind hero XP when the character is several levels behind and I specifically want that hero for the next difficult stage.

Difficulty and game mode can change the rate as well. Impossible gives 1.5× hero XP, Blitz and Hero Party give 1.25×, and Classic Rush gives 1.5×.

For skill choices and which heroes are worth keeping active, use Best Heroes & Hero Pairs.

Player Spells Level Through Casting

Spells use another independent progression track.

A spell gains XP when it is cast and can reach Level 6. After Level 1, each level gives one upgrade point, so a fully leveled spell has 5 points to spend.

The tree contains 8 upgrade nodes, but you cannot activate all eight at once. Levels 2 and 4 each contain a two-way choice, while the Level 5 upgrade follows whichever Level 4 branch is active.

Those branch selections can be changed without locking the spell permanently into one build.

The game also applies a catch-up factor to spell XP.

If a spell is two or more levels below the expected level for the number of campaign stages you have unlocked, casts give double XP. Being two or more levels ahead cuts the gain in half.

This is another reason not to stop campaign progression just to grind the first two spells indefinitely.

Missing spell XP can also be bought with Gems. From Level 1 with no XP, taking a spell all the way to Level 6 costs 2,400 Gems, so I treat that as a shortcut for a spell I actually plan to use rather than automatically leveling the whole roster.

The strength of each spell and the useful upgrade branches are covered in Best Spells & Spell Tier List.

Challenge Stars Become Important After the Campaign Opens Up

Every completed challenge awards 1 Star.

That makes challenge modes the main source of Stars once the Campaign’s maximum 54 have been collected. You do not need to clear them all before progressing, but they become increasingly useful when the next Steam unlock sits beyond what the remaining Campaign Stars can provide.

I usually return to a challenge when one of three things is true:

• the next unlock is only a few Stars away;
• the normal version of the stage is already familiar enough that the altered rules are the only new problem;
• I am combining the Star with an achievement or difficulty cleanup.

Forcing every challenge immediately after every Campaign victory slows the roster progression more than it helps. Later towers, heroes and spells often make those older challenges easier when you return.

Impossible Unlocks at 60 Stars

Impossible difficulty requires 60 Stars.

The option appears in the difficulty menu before then, but it remains locked until the account reaches the requirement.

Permanent upgrades, hero levels and spell levels can make the Star cleanup easier, but none of them replace those 60 Stars.

Once you are close, campaign cleanup and already-unlocked challenges become more efficient than forcing a difficult new battle for no Star advantage.

Reaching 60 also does not finish Steam progression. The later Steam roster continues through Thunder Zapper at 62, Illiana at 66, Wintersong’s Wrath at 68, Oni at 70, Aspect of Sol at 72, Drakkan at 80 and Ashbite at 84.

Impossible itself becomes useful for leveling heroes because it awards 1.5× hero XP, so the difficulty can contribute to later roster development rather than existing only as a completion badge.