Border Down mechanics : This game is named 'Border Down' because it has a new approach to level design : you can choose, at the beginning, your border to start the game on. Every stage has 3 borders : green, yellow and red ('easy', 'middle class', 'maniac' difficulty).
Every time you get hit, you will move one border down, and thus go from green to yellow border, then from yellow to red, then it's game over if you get hit on red border.
Border Down weapons :
1) Forward laser : it is shot by holding down the 'A' button and it's a frontal (left to right) stream. Now, one thing you will surely notice is that your power level seems not to be 'homogeneous' : the level 1 forward laser is narrow, but pretty powerful, almost like a piercing attack, even more than the wider level 2 attack. Don't be fooled : the level 2 attack is better, you just need to aim all the bullet streams on the enemy. The same discourse is valid for the level 3, level 4 and level 5 shots, bearing in mind that that they're even wider, so point-blanking the enemy becomes the best option in some cases, in order to place all hits on said enemy. Also, the closer you are to the right side, the higher the fire rate is. This means that if you're close to the right side (or an enemy), you will shoot more lasers. Point-blank or close-to-right-border positions will grant you a rate close to auto-fire... the inverse phenomenon will appear if you're close-to-left or very distant from enemies,of course.
2) Homing laser : it is shot by tapping the 'A' button, and is pretty useful when dealing with enemies from all angles, but its lower fire rate renders it almost useless when dealing with tougher (and larger enemies). A wise mix of both attacks can be pretty devastating, though. Damage is actually the same, if you compare the two different attacks. One interesting thing is that, if you destroy an enemy one of your homing lasers was going to hit, the laser will change target : if it can't hit targets, it will go outside the screen. The point-blank discourse is valid for this attack too, you still have to tap when shooting, of course. Once we have explained what are the basic attacks controlled by the 'A' button.
3) Break laser (BL) : it is your smart bomb and the key to access higher scores (more on this in the score section). It's simple to use it : press 'B' button and hold it if you need to. It's usage is limited by the amount of energy you have in stock. When triggering the laser, you will immediately consume half a bar of energy, and after a second the energy will start going down at the rate of 1 bar every ~2.5 seconds (not absolutely sure). This actually means that you can you can shoot a continuous BL for ~12.5 seconds, provided that you don't get killed or you trigger a Break Laser Sphere. The damage the laser does can be considered as roughly about twice the damage dealt by a full level 5 forward shot at point blank.
The BL has also a far more important purpose: it cancels all bullets on its path (but see below for some notes). Aside increasing your score, it also helps 'cleaning up' the screen from unpleasant messes of bullets. Actually, the are two attacks that can't be canceled by the BL : the floating mines (they will explode if hit, though) and one attack from the 6A/6B final boss.