2 game types are available: in pillpop you're clicking pills that have at least 2 more of the same color next to them, either another pill or a virus, but the latter is not clickable. 3 same-colored pills turn into a rainbow pill that can be matched with anything and it's possible to cover a lot of ground with it. viruspop is a lot easier, you're clicking groups of viruses and the only pills are rainbow ones created from bigger groups.
both game types can be played on small (8x8), normal (10x10) and big (12x12) boards with 4 or 5 colors and in 3 game modes: zen is untimed and ends at level 20, blitz is a 2-minute score attack and survive lasts until the board is filled. it's a bit like tetris, what with new rows appearing after certain intervals. I found zen a bit tedious, it takes a while to finish, but the other two are a lot of fun and survive gets really crazy on higher levels.
the presentation is fine. the graphics have that '90s shareware vibe for those who remember, cute viruses with googly eyes, and the soundtrack offers a variety of genres, you can even customize the playlist, but sadly my favorite tracks (including the one in the trailer) are way too short.
all the necessary settings are here: separate volume sliders, windowed mode (fixed size, no resolutions), color blind mode, plus in-game help explaining the game types, stats, online leaderboards for all the different variations, even in-game representation of achievements.
I really enjoyed the game, works both as a relaxing experience and a hectic one, can be enjoyed alone or played competitively, has that 'just one more try' feel to it and the price is absolutely fair as well.