Sine Mora....coz its a really nice piece of design. The story mode is very easy but when played in arcade mode the time extend mechanic really shines. Forcing the player to attack rather than defend, to engage with enemy patterns and bosses in a very different manner to story mode. Btw..did you play the tutorial stage by going through the tunnel section? That is ♥♥♥♥♥♥♥♥♥♥♥♥♥ hard. Don't.