The eternal trials are the only alternative gamemode besides the main levels. In contrast to the normal maps, the eternal trials are an endless mode. Just like rogue-like games, the players loses all progress and power-ups upon being defeated.
The eternal trials consists of stages. At the start of each stage the player is offered three options. Each option shows a map, a weapon and two perks. After the player has chosen an option, they will have to play on the selected map with their respective weapon and will obtain the two chosen perks for the rest of their run. This means that the player has 2 perks on stage 1, 4 perks on stage 2, 6 perks on stage 3 and so on.
While the maps, weapons and perks are chosen by the player, they have to fight a randomised set of enemies each stage. The player has to face a random number of waves per map. The enemies in each of those waves are also randomly generated, meaning the player will face enemies that do not normally spawn on a specific map (see below for more details on wave generation).
If the player manages to beat all the waves, they move on and are able to select the map, the weapon and the two perks for the next stage. The difficulty of the game increases with each stage (see below for more details on difficulty increases). After the players castle center eventually gets destroyed, they lose. All of their previous scores from each stage will be added together and the player receives a score bonus, increasing with each stage they have won. The stage bonus is calculated using this formular: (Won Stages)² × 10 000. After the player has received their final score, they lose all their perks and they may start another run.
At the start of each stage, the wave generator uses a bunch of chances to determine which patterns the waves of the stage will have. Some possibilities are: Mono-battle stages, where you encounter the same one enemy type in every single wave (1.7%) and Mono-spawn stages, where enemies only spawn from one spawn point (10%).
Additionally, other parts of the stage are determined, such as:
From stage 5 onwards the player always starts each stage with at least 11 gold.
The amount and power of enemies for each wave are determined by the amount of difficulty points. Difficulty points are a hidden statistic, purely in the background of the game.
The amount of difficulty points per wave is determined by a complex calculation in the background of the game. It considers the current stage (the first 7 stages the difficulty increases exponentially, after that linearly), spawn location proximity to castle center (single multiplier), wave length (exponential) and simulated economy (this includes and is dependent on starting gold).
When creating waves, the game spends the difficulty points to spawn enemies. For example 18 per exploder.
| Enemy | Difficulty Points |
|---|---|
| Archer | 1.6 |
| Catapult | 6 |
| Elite Crossbow Man | 3.5 |
| Exploder | 18 |
| Hunterling | 2.4 |
| Monster Rider | 3.3 |
| Ogre | 17 |
| Peasant | 0.6 |
| Racer | 5 |
| Ram | 18 |
| Slime | 1 |
| Spiky Slime | 4.25 |
| Swordsman | 2 |
| Wasp | 5 |
| Pikes | 3 |
| Fury | 13 |
| Barrel Knight | 7 |
| Flying Mage | 8.5 |
| Mole Knight | 6.33 |
| Mole Archer | 4.88 |
| Quicksling | 18 |
| Elite Enemies | (Normal Version Difficulty Points) x6 |
As stated above, the game simulates the players economy on every given stage to increase the difficulty according to the amount of gold the player has at their disposal.
The game starts to simulate the players economy on day 1. It assumes that they put 50% into economy and 50% into defenses. The game also assumes that all economic buildings survive and calculates the players gold gain for the next day, which is again spent 50/50 in economy and defense. On the last two days, the game expects 100% of the available gold to be spent on defenses. This way the game consideres the total defense spending for each wave, by adding all previous defense spendings together.
In the end, the difficulty points are increased each wave, proportionally to the total defense spending up untill that respective wave.
Some enemies have a "Gold Limit" value. It determines the minimum amount of gold the player has to have in defenses (according to the simulated economy), for it to be able to spawn.
Elite enemies are a special kind of enemies, that are unique to the eternal trials. They have 4x the hp and 3x the damage of their normal counterpart and are highlighted in the game by a special golden and spiky icon, as well as a golden outline.
Elite enemies are converted from 6 normal enemies of their kind (and therefor also cost 6x their difficulty points) based on pre-generated patterns. If the total number of enemies exceeds 200, enemies are merged into the elite version of themselves, until the total number of enemies is below 200.
Eternal Trials in the level selection
Stage - Loadout selection