Speedrunning, precision platforming, and collect-a-thon goals are what you'll find in WIWI Games', "The Legend Of Gwen". This 3D witch versus evil adventure comes with minimal plot, and to the point gameplay with gated features locked behind an in-game paywall. Not a paywall in the real money sense, but a paywall wherein stars and crystals collected will open up new areas in the game's base hub.
In total you'll find 7 uniquely themed moons with point marked stages, and boss battles. Each stage is a themed and timed event where speed running your way through to beat that timer will bank you some bragging rights if not rewards. While in each stage lives are limited, and items that must be collected specific in number. You'll find crystals, stars, and chests that when collected in full will grant you a 100% completion. Allowing you to not only move on to the next stage, but also to spend the items on base unlocks. Things like spells, and bonus mini-games that have their own rewards for effort rendered.