v0.3

This version should be released by yesterday, but there are some things I need to settle first so the delay has been made...

Anyway, the changes are listed below:

[ ADDITIONS ]
- Added Main menu, you can start new game or tutorial level, go through the settings.
- Added Tutorial level: You access the level by clicking "Start Game" and then choose the first option.
- Added the second level for playthrough, and your current ammunition count will be carried over when entering this level.

- Added target doll: You can shoot at them to get acquaintance with the game mechanics, they are added in the Tutorial level and also Main menu for enjoyable view.
- Added zoom-in aim - energy submachine gun: You can see the targets from afar clearer, firing spread becomes tighter and slightly harder to move your aim.

[ TWEAK ]
- The plasma burst gun: Alternate firing will use 4 ammo instead of 2, but it shoots more pellets than before. Its base attack damage is decreased, for more pellets to have more consistent shot for both primary and alternate firing mode.
- The shooter enemies are now be able to often dodge your shooting, but they can be shot at once to be killed before they noticed you.
- The turrets have slightly more durable than before.
- The first level's map placement has been changed a bit.
- All penetrable walls types have their own stats tweaked, drastically affect the projectiles stats from now on.
These changes above are made to balance out as much as possible I can think of, since the multiple levels and remaining ammo count are introduced which I have planned for this experimental game during the development stage.

I think that's all, hope you enjoy the latest version of the game!