8 Bit Tower Defense Progression Guide: What to Do Next and What Unlocks It

Figuring out what to do next in 8 Bit Tower Defense comes down to two tracks that feed each other: the story worlds you clear in order, and the modes, rewards and unit goals that unlock along the way. If you are brand new, the how to play guide covers placement and match basics first.

Quick answer

Clear story acts in order: each world's Act 6 unlocks the next world, all the way to Ashen Citadel, and clearing Ashen Citadel unlocks Raids. Along the way the Play menu opens World Boss (Tide Titan) at Greenfield Outpost Act 3, Challenges at World 1 Act 6, and Expedition at World 2 Act 4. Between matches, level units with gold in UNITS > LEVEL UP, summon for new units and Index gems, and reroll traits and trades.

• Story chain: Sakura Shrine unlocks after clearing Greenfield Outpost Act 6, Dustbowl Canyon after Sakura Shrine Act 6, Frostbite Pass after Dustbowl Canyon Act 6, then Ashen Citadel.
• Mode gates in the Play menu: World Boss (Tide Titan) needs Greenfield Outpost Act 3 cleared, Challenges need World 1 Act 6 reached, Expedition need World 2 Act 4 reached, Raids need Ashen Citadel cleared.
• Core unit loop: gold from battles levels units (each level adds damage), SUMMON x10 costs 500 gems, and the Index pays gems for new discoveries with a CLAIM ALL button.

The story track: clear acts, unlock worlds

Story is the spine of progression. The story list in the Play menu shows every world and its acts so you can pick your next battle, and clearing an act opens the next one. Every world runs 6 acts, and each world after the first is gated behind Act 6 of the one before it — so the fastest route to any late-game mode is simply advancing the story. The official game description advertises 6 story worlds in total, running from Greenfield Outpost to the Hollow King's Ashen Citadel.

Roadmap

1. 1

   1. Greenfield Outpost (World 1)

   Clear all 6 acts. Clearing Act 3 unlocks the World Boss fight against the Tide Titan, and clearing Act 6 opens Sakura Shrine and satisfies the Challenges gate.

2. 2

   2. Sakura Shrine (World 2)

   Unlocks by clearing Greenfield Outpost Act 6. Reaching Act 4 here is what opens Expedition.

3. 3

   3. Dustbowl Canyon (World 3)

   Unlocks by clearing Sakura Shrine Act 6.

4. 4

   4. Frostbite Pass (World 4)

   Unlocks by clearing Dustbowl Canyon Act 6.

5. 5

   Ashen Citadel (final advertised world)

   The captured menu chain shows Ashen Citadel following Frostbite Pass, and the official description advertises 6 story worlds ending here, so its exact slot and the full six-world list weren't confirmed from the capture. Clearing it is what unlocks Raids.

For a closer look at each stop, see the 8 Bit Tower Defense worlds list and the story mode guide.

Every mode unlock gate

The Play menu lists a requirement next to each mode beyond story. In the order you can realistically reach them:

Note the difference in wording the menu itself uses: World Boss and Raids ask you to clear an act or world, while Challenges and Expedition only ask you to reach a point — so Expedition opens while you are still working through Sakura Shrine, before you finish it.

What waits behind each gate: the World Boss is the Tide Titan. Challenges are rotating challenge runs. Expedition sends one squad through three worlds and lets you pick a Relic after every win. Raids are co-op for up to 4 players across Rift Gate, Coral Cove and Eclipse Spire. There is also Infinite mode outside the gate list, and every mode can be set to Normal, Nightmare or Legend difficulty in the play setup. Details live in the game modes overview, the raids guide, the expedition guide, the challenges guide and the difficulty levels page.

Unit goals worth working toward

Level your squad with gold

Gold from battles levels up your units: open UNITS, press LEVEL UP, and each level adds damage. Squad units also gain XP from every match, so simply running acts progresses them. The starting hub tutorial hands you 500 gold and 2 Trait Rerolls to begin this loop. More on both currencies in the gold guide and the leveling guide.

Summon units and feed the Index

SUMMON x10 costs 500 gems, with the rates shown on the summon screen: Rare 70.74%, Epic 26%, Legendary 3%, Mythic 0.25% and Secret 0.01%. Every new unit you discover is recorded in the Index, and the Index pays gems for new discoveries — observed payouts include +375 gems for 13 discoveries, +360 for 5 and +240 for 4, collectible with a CLAIM ALL button. Early on, that makes summoning a repeatable gem source, not just a unit source. Event exclusives appear on top of the standard pool, such as the Hollow Night event's Headless Horseman (Secret, 0.02%) and Grim Reaper (Mythic, 0.5%).

Useful next steps: the units list, how to get units, unit rarities and how to get gems.

Traits, trades and Mythic evolution

Trait Rerolls are spent in UNITS > TRAITS: press REROLL to roll a new trait with a dice. Traits add damage, range, cash and more — the tutorial's example roll produced SWIFT I, 5% faster attacks. The Trades tab works in parallel: trade rewards sit there, and re-rolling a trade with a dice can produce effects like Vigor (+5% damage), again adding damage, range, cash and more. Further out, the game advertises evolving Mythics into stronger forms; one creator has observed that not all units are evolvable, so check a specific unit before planning around it. The description also advertises hunting for Shiny units — see the shiny units page. More detail: the traits guide, how to get trait rerolls and how to evolve Mythic units.

Rewards that stack with everything else

The account has its own level with an XP bar in the HUD, and squad units gain XP from every match. The Quests > LEVELS tab shows level rewards up to Lv 50, and one achievement asks you to reach account level 10.

Achievement-style goals include defeating 10 bosses, winning 10 matches, summoning 100 units and discovering every unit. Achievements pay gems — a 100-gem claim was observed — while quests pay diamonds, with achievements listed at 250–2,000 diamonds.

Before grinding anything, claim the one-time group reward in Settings: liking the game and joining the Roblox group pays +100 Gems and +1 Trait Reroll from the CLAIM button. The same Settings screen holds the CODES redeem field — current codes and their rewards are maintained on the codes page. More reward sources: the group reward page and how to get gems.

A working order for your next sessions

Checklist

• Claim the free group reward in Settingshigh

  Like the game and join the Roblox group, then press CLAIM for +100 Gems and +1 Trait Reroll. One-time only.

• Push Greenfield Outposthigh

  Clear Act 3 to face the Tide Titan, then clear Act 6 to unlock Sakura Shrine and satisfy the Challenges gate.

• Level units and reroll traitsmedium

  Spend battle gold in UNITS > LEVEL UP (each level adds damage) and use the 2 starting Trait Rerolls in the TRAITS tab.

• Summon and claim Index gemsmedium

  Run SUMMON x10 for 500 gems and collect discovery rewards in the Index with CLAIM ALL.

• Chase the mid-game gatesmedium

  Reach World 1 Act 6 for Challenges and World 2 Act 4 for Expedition.

• March toward Ashen Citadellow

  Clear each world's Act 6 through Frostbite Pass; clearing Ashen Citadel unlocks Raids.

And whenever you are unsure what comes next, open the story list in the Play menu: the act you have not cleared yet is the answer, and every other mode and reward loop in the game hangs off those clears.