[Guest reviewer Colin Brown profiles each game in the July Jubliee Bundle, now available at IndieGames' co-created site: Indie Royale.]

If I had a dime for every indie game with a retro aesthetic, I would have an impressive mountain of change. The indie movement certainly loves its pixels, and for good reason. It's generally far easier and cost effective to use sprite art, it can look really amazing in the right hands and gamers are a notoriously nostalgic bunch. However, 99% of retro lookalike indie games don't fully commit to the old school style. Maybe the mechanics are a bit friendlier, or perhaps they use modern graphic technology to cheat in terms of palettes or special effects. Oniken is not like 99% of retro inspired indie games.

Five minutes into the first level of Oniken and I was almost convinced that Danilo Dias simply found an obscure NES title, slapped it into an emulator and sold it. Believe me, Oniken has that level of accuracy. Everything from the sound design, sprite artwork, limited palette, controls and, of course, the difficulty screams vintage Nintendo. The only remote indication that this might actually be a modern game is the presence of a Vsync option and some 8-bit decapitations that might have caused problems with scoring a Nintendo Seal of Approval.

When is the last time a game actually asked you to press the start button to start? Maybe that's a small thing to fixate on, but it really is symbolic of just how much of an eye for detail the developers have. Like many NES games too awesome to be made today, you are a ninja hero fighting a rebellion against a corrupt world order. Using a cutscene style straight out of Ninja Gaiden, the hilariously convoluted plotline unravels as you go from a factory to a battleship to the obligatory train level. It's all very creative; it's bizarre that despite the way Oniken limits itself, the game still feels like it's pushing boundaries. The catch is that it's 1989 boundaries instead of 2012 ones.

It's also hard. There's a reason the term Nintendo Hard exists, and Oniken fits right into that model. It's a game that punishes the lazy, the sloppy and the careless, requiring absolute perfection, a bit of memorization and really sharp reflexes. All of your old enraging NES quirks are at work here, like damage that throws you backwards, awkward Canstlevania style weaponry and a very limited life pool. The one grudging allowance the game makes is the ability to continue from the beginning of each level, but that's barely enough to even the odds. If you grew up on a steady diet of impossible NES challenges, Oniken is a marvellous throwback. It's possibly the most accurate NES homage out there, right down to the crushing difficulty.

[Get Oniken, all five Geneforge Saga titles, Puzzle Agent and three other games in the July Jubliee Bundle, now available at IndieGames' co-created site: Indie Royale.]