100 Trials is a spinoff from the same developer's excellent 100 Rogues, but really it's best described as a mission pack. The original is a roguelike for iOS with a slim challenge mode, and it's the latter that 100 Trials expands into a gauntlet of bite-sized puzzles.
Each trial has an assigned rogue, each of which have their own play styles and movesets (which are limited according to the challenge), and presents one objective - often but not always escaping from the level, or killing all monsters. There's no random generation here, either, with each trial fixed in its enemy types and placements.
The challenge is in learning how to predict its enemies, a deceptive-looking bunch that have learned several new tricks since 100 Rogues. Though many sprites make a return appearance, most creatures have slightly rejigged moves and behaviour. Learning how enemies operate is the key skill, and they all have behaviour that is predictable up to a point but with one or two surprising kinks to take unwary players off-guard.