Undertale Adventures X is a Roblox tower defense title developed by Side Productions that tasks players with deploying iconic Undertale characters to protect their home base from incoming enemy waves. Successfully completing stages rewards players with Souls and XP, which fund unit summons and account progression.
To build a reliable defense across standard missions and endless challenges, you need to understand core stage economy, identify which early units are worth placing, and target endgame boss killers like Mettaton NEO.
Core Gameplay and Controls
Battles in Undertale Adventures X follow a wave defense layout. At the start of each stage, you receive a limited balance of in-game cash. Defeating enemies provides additional mid-battle funds, which you spend during the match to deploy units or purchase upgrades on existing towers.
Basic character movement and environment controls use standard Roblox keybinds:
- W, A, S, D: Movement
- Spacebar: Jump
- E: Interact
Each loadout allows you to bring up to five party members into a match. You are not limited to placing a unit once; you can place multiple copies of the same character across the map as long as your mid-battle cash allows it. Between matches, units can be leveled up and customized with traits to increase their battle effectiveness.
Stage Progression and Difficulty Modes
The main campaign features linear stage progression where enemy waves reach into the tens and include periodic minibosses and stage bosses. When setting up a stage, you can select between three difficulty tiers:
- Pacifist: The easiest and most beginner-friendly setting, designed for starting teams.
- Neutral: A balanced difficulty setting recommended for standard play.
- Genocide: The highest difficulty setting, introducing intense enemy waves that demand optimized party rosters.
Beyond the linear story stages, players can participate in Infinite Mode, an endless survival challenge that scales indefinitely and tracks high scores on a public leaderboard. The game also includes Raids mode and an AFK Chamber sub-place for supplemental progression.
Undertale Adventures X Best Starter Units
When you first join the game, you begin with two default units and can expand your roster through Souls summons or stage drops. Early-tier units help stabilize opening waves on Pacifist and Neutral difficulties, but their combat efficiency varies dramatically once wave counts scale up.
| Starter / Early Unit | Tier | Role | Strengths and Limitations |
|---|---|---|---|
| Temmie | B | Glass Cannon | Delivers solid early-game DPS; suffers from low defensive scaling in prolonged rounds. |
| Froggit | C | Basic DPS | Dependable starter attacker for clearing entry waves; lacks endgame damage scaling. |
| Loox | C | Basic DPS | Basic early single-target damage dealer with better late-game scaling than Froggit. |
| Migosp | C | Basic DPS | Baseline attacking unit with low late-stage damage potential. |
| Vegetoid | C | Minor Healer | Provides minor party healing output, but contributes minimal attack damage. |
| Snowdrake | D | Ranged DPS | Starter ranged unit suited only for initial wave control. |
| Ice Cap | D | Utility / Weak DPS | Early utility damage dealer with poor damage output after opening waves. |
| Dummy | D | Gimmick | Situational placement with very low overall damage contribution. |
Starter Strategy: Managing Fall-Off
Early units like Froggit, Snowdrake, and Ice Cap provide inexpensive coverage to eliminate early creeps while you accumulate deployment funds. However, community tier lists categorize Froggit, Migosp, and Vegetoid in C-Tier, with Snowdrake and Ice Cap falling into D-Tier due to steep drop-offs in damage scaling.
Temmie (B-Tier) serves as the most potent early-game damage dealer among non-meta picks. While Temmie operates as a glass cannon with weak defensive scaling, placing multiple copies early allows you to quickly thin out entry mobs and save mid-game cash for high-tier summons. Once you transition toward Genocide difficulty and Infinite Mode, plan to replace pure starter units with AoE sweepers like Sans or Asriel and durable frontliners like Undyne the Undying.
Undertale Adventures X Mettaton NEO Showcase
Mettaton NEO ranks in S-Tier as the premier Boss Killer in Undertale Adventures X. While mob-clearing units prioritize wide damage arcs, high-health bosses and endgame elites require sustained, high-intensity damage before they breach your base defenses.
Strengths and Role in the Meta
- Highest Single-Target Damage: Documented meta evaluations rank Mettaton NEO as possessing the highest single-target DPS in the entire game.
- Dedicated Boss Elimination: Specifically clears stage-ending bosses that stall or overwhelm AoE-focused setups.
- Endgame Scaling: Unlike starter units that peak on opening waves, Mettaton NEO excels during late-game waves and deep Infinite Mode runs.
Because Mettaton NEO focuses exclusively on boss busting, pairing this unit with crowd control and front-line support is necessary. Meta rosters commonly place Papyrus or Muffet to apply crowd control and slow down clusters, alongside Undyne the Undying or Asgore to anchor the lane, leaving Mettaton NEO uninterrupted to melt the primary target.
Specific numerical base stats, precise summon drop percentages, and trait roll values for Mettaton NEO are unconfirmed in available documentation.
Official Gamepasses and Progression Boosts
Players can accelerate their summoning and leveling through optional store passes purchased with Robux:
- Supporter (200 Robux): Grants a 10% Summon Discount, +15% Underpass XP, and an exclusive Title and Chat Tag.
- 2x XP (300 Robux): Doubles unit and profile experience gains.
- +50% Tokens (300 Robux): Grants 50% more token currency when completing Raids mode.
- VIP (500 Robux): Premium member perks.
- SHINY Hunter! (1,000 Robux): Increases the odds of obtaining shiny unit variants.
Frequently Asked Questions
Which difficulty should new players start with?
Pacifist is recommended for players using standard starter units such as Froggit or Snowdrake. Once your party is expanded with B-Tier units like Temmie or A-Tier anchors, Neutral provides standard progression without the punishing waves of Genocide mode.
How many units can be equipped in a single match?
You can equip five party members in your team lineup. During an active stage, you can deploy multiple copies of those five equipped characters on the map, provided you have sufficient mid-battle funds.
What makes Mettaton NEO better than general AoE units?
Units like Sans and Asriel specialize in wide AoE crowd control and mob clearing. Mettaton NEO is tuned specifically for the highest single-target DPS in the game, making the unit essential for defeating high-HP bosses that AoE damage cannot eliminate quickly enough.
