In Locomalito’s Viriax your goal is to swim up through the organs of human beings and infect their cores before your energy runs out. You start with one attack – press down or X to drop onto enemies and destroy them, obtaining combos for destroying multiple enemies within a small timeframe. Attacking serves a couple of other purposes – it renders you invincible temporarily and you can use it to reveal power-ups (or power-downs).
Each time you jump in mid-air or attack in Viriax your energy level goes down slightly, so you have to conserve your movements and use power-ups wisely. You can replenish your energy with red globules, which are also released occasionally by destroyed enemies and can also be found floating around the levels. It’s a smart system that creates a lot of exciting moments as you carefully wind your way up the bloodstream.
The levels are randomly-generated and the power-ups vary pretty wildly in usefulness, so there’s a degree of luck involved. In terms of scoring, the keys are extremely overpowered, so the main purpose of high scores seems to be for unlocking the later levels. In general, though, the challenge ramps up nicely and I had a great time attempting to infect each of the organs, from the lightly defended Heart all the way up to the N.A.S. itself.
TIGdb: Entry for Viriax