Waves of encounter

Update on several stuffs

Major update

- the first encounter on each level will be wave encounter. This to introduce player to several opponent in isolated manner

- introduce stage hazard 

New content

- add drill construct which will move in straight line and pierce your enemies

- add seeksword that behaves like sword in star force. It will go to nearest target which has HP (obstacle or enemies alike)

- add buzzer variant which turns player affinity to fire and water

- add blower enemy that push player to back row.

- new BGM for opening scene

- add cutscene after level1

Bugfix and minor update

- story part uses wrong font. It is supposed to be same with the rest of the game

- the move up-down on inventory scene is now moves in an instant

- add forgotten enemy tag to some enemies