extends work like any other STG, you get em by scoring
the score counter fills from orange to yellow indicating how close to an extend you are
the first few are really cheap, ex: a decent stage 1 run will get you 3 extends.
scoring is a simple chain multiplier: hit things to increase your multiplier, which maxes out (MAXIMUM) at 6.4x. at a certain point (robotform!) this limit is doubled. The score counter will run down when you aren’t killing things,when you scrape a wall or collide with something, or when you die. the higher your multiplier is, the more quickly it runs down when not killing things, though the difference is pretty small i think.
get the bonus items if you can find them, there’s 3 per stage, i can post the locations of the ones i know about if you like. they are at least worth one extend on their own if you collect all three in a stage.
orange enemies are extras: they appear when you destroy a green enemy wave quickly enough
those ships that reveal a skull-face when you blast them enough: when you do that, the skull will release eight big flower bullets which can be destroyed and have high base value. if you can time it right, these are The Big Score
you can get double the score off of most big enemies if you keep shooting them for about a third of a second after they’re down: they will flash white when it happens
there are a few secret 1up items hidden about that i know of
NOCODE’S BURNING QUESTION: does this game have a rank system