I think this is a solid start to a game, simple but effective! I did have a few ideas for how you could expand it if you wanted to:
First I think the masks are too plentiful, by the time I stopped playing I had a score of over 2,000 and over 150 masks, so lowering the number would make them more desirable to try and obtain. You could also maybe make them give you 1-2 seconds of invulnerability instead of just subtracting 1 from the mask count. I also think adding more variety to the obstacles would add to the replayability. Some ideas are different sized/colored viruses, some that could move from side to side at different speeds, large pillars that block the way and cause you to stop entirely, or just gaps in the road that require you to jump.
I hope you keep developing this after the jam is over!