In the Roblox experience Periastron Tower Defense (created by Periastron Champions), unlocking new units is centered on purchasing and opening crates from the in-game shop. Players spend earned currencies—such as Coins, Runes, and Shards—to roll random unit cards that can then be placed into an active loadout for defense matches.
How to Unlock Units via Crates
According to official game details and gameplay recordings, unit acquisition is crate-based. Players cannot simply buy individual towers directly off a static shelf; they pull them from crates available in the lobby shop.
- Access the Lobby Shop: Navigate to the crate vendor or card shop area in the central lobby.
- Select a Crate Type: Crates come in different categories and tiers, including themed variants such as the Nature Crate or rarity-tinted boxes (such as green and blue crates).
- Spend Currency: Purchase crates using Coins or Runes. Once bought, open the crate to reveal your unit card.
- Equip in Backpack: Open your inventory/backpack to equip your newly unlocked units before stepping into an elevator or matchmaking portal.
If you are just starting out, the game provides basic starter tools, such as the Slingshot and basic melee options, so you can earn enough currency to start opening crates.
Confirmed Units and Recorded Stats
Gameplay testing and developer updates have revealed several distinct units, spanning rapid-firing ranged attackers, melee swordsmen, and crowd-control specialists.
| Unit Name | Base Stats / Attack Behavior | Key Combat Traits Observed |
|---|---|---|
| Slingshot | 7 Damage, 12 Range | Basic single-target ranged starter unit. |
| Sword | 35 Damage, 2.0s Cooldown | Melee unit delivering heavy single-target strikes. |
| Slasher | 5 Damage per hit (rapid strike) | Fast-hitting melee alternative to the Sword. |
| Frostion | 10 Damage, 10 Range, 1.0s Cooldown | Slows targets upon hit; purple (Epic) drop. |
| Cryomancer | Knockback / Slow | Knocks enemies backward along the path while slowing them down. |
| Bonfire | Rapid continuous fire | Minigun-style persistent projectile stream. |
| Rocket Man | Area-of-Effect (AoE) | High-damage explosive clearing grouped enemies. |
| Archer | Ranged projectile | Mid-range physical targeting with low cooldown. |
| Vault | Defensive / Support | Tested in Update 2 footage; exact scaling is unspecified. |
| Vindicator | Combat card unit | Unlocked from Update 2 crates; full damage scaling unconfirmed. |
Methods to Earn Coins and Crates Faster
Because unlocking units requires continuous crate purchases, collecting Coins and Shards efficiently is essential to building a solid roster.
Completing Match Challenges and Contracts
Checking the contract board in the lobby provides bonus payouts. Common contract objectives include:
- Dealing specific total damage milestones (such as 30,000 cumulative damage).
- Defeating targeted enemy counts (such as 100 total enemies).
- Hour-based playtime objectives that reward active grinding over time.
Reaching Level 3 for Code Redemption
Players looking to use promotional codes for free Coins and Shards must first reach Level 3. The code redemption menu in the settings interface remains locked to accounts below this level threshold. Once Level 3 is reached, codes reward flat Coin injections and Shard fragments that can immediately fund crate purchases.
Store Game Passes
For players using Robux, the official developer store offers permanent progression passes that directly influence crate costs and unlock speed:
- VIP (319 Robux): Grants a permanent 20% discount on boxes, a 25% bonus EXP multiplier, and 10% AFK rewards.
- 1.3x Luck (299 Robux): Provides a 30% increase to pull luck when opening crates.
- 2x Coins (399 Robux): Doubles Coin earnings from all matches.
- 1.5x Shards (399 Robux): Multiplies earned Shards by 50%.
- Skip +5 Total Card Requirement (199 Robux): Bypasses the five-card deck prerequisite.
Viewing Unlocked Units in the Index
Periastron Tower Defense features an Index tab located directly in the lobby menu. The Index catalogs every unit, card, and enemy variant you have discovered or collected. Interacting with the Index displays the full 3D character model of the unit, allowing you to review your collection status and prepare balanced teams across crowd-control, melee, and rapid-attack damage roles.
