The gameplay is quite simple. First of all , you have to keep rythm bar’s level high, for 2 reasons:

1) To increase score multiplier.
2) If rythm bar’s level is too low , you start losing HP over the time.

To increase rythm bar’s level , try to complete as many as possible wall-beat instructions sync’ed with background music, by jumping off the (flashing)walls.

Changes:

-You can now break in pieces big enemies -lol-.
-New particle effects
-Different attributes for each weapon
-Different particles for each weapon
-Smoother particle effects
-Added new power-up (SHIELD)(has a small ammount of hp)
-Added animated effects for shield.
-New power-up icons.
-Added new boss-type enemy.
-Added new enemy type.
-Improved AI system(added more states , and mainly used by the new enemies).
-Added menu sounds.
-Added more particle effects(for bombs).
-Highlighted (menu) elements are now flashing.
-New score text effects
-Added menu sounds(nav/confirmation).
-Lowered down power-up timer.
-New theme
-New theme effect
-Some misc code optimizations.
-Updated level editor to v1.c (from v1.a).

http://forums.qj.net/showthread.php?t=140775