Control your sparky unicellular protagonist with [WASD] or the [arrow] keys. You can switch between weapons with [space], and aim and fire at foreign organisms with the mouse. When enemies drop colored hunks of DNA, you can pick them up and aim them at the larger strand of DNA being processed around you. Holding a DNA bit makes you temporarily invincible, but you can only hold it for a short while. Like Zuma, creating a sequence of three or more of the same color causes it to disappear, which is good. You need to score a certain number of these sequences, delineated by the progress bar at the top-left of the screen, to beat each level. Create combos, blast interlopers, collect power ups, and save your host from dire infection.
Alkemi kindly lets you start any level at any time, but I would recommend starting at the beginning nonetheless. As there are merely 9 levels, the difficulty ramps up pretty quickly. The serene backgrounds and soothing soundtrack belie how tense the game gets by mid-levels. It's challenging, very nicely produced, and cleverly combines two types of gameplay into something novel and fun.