Life isn't fair, and neither is Eryi's Action. This game is a pretty, stylistic, precision-controlled, fiendishly difficult platformer. At first glance it looks and plays like an anime Mario Bros, but a few minutes' gameplay will dispel that idea. Eryi's Action throws a variety of clever and/or cheap traps at you, For instance, in many places, the ground will just drop out from underneth you, sending you to your death. In other places an enemy might drop out randomly from the sky at an inoppotune time, or spikes might shoot up out of a pit while you're jumping across. Anything easy is likely to be a trap, and, after a while, you'll start anticipating some of the traps.
There's a true beauty to the gameplay here, Eryi's Action establishes early on that the game is not fair, nor does it intend to be. If you can tolerate and embrace this mindset, and if you don't mind dying literally hundreds of times, then you'll enjoy the game. Eryi's Action is beautifully made, the platforming is precise, the graphics are lovely, and the game features not just platforming, but some flying/shooting sections, swimming, a clever RPG-style boss fight, and some very clever physics puzzles. All of it is brutally difficult, it's a match of wits between the programmer and yourself, a battle against unfair odds. It's a true gem, if only for the most hardcore of gamers.