Hey dude, apologies for my late reply!

I did play with your game, here what I have found a little weird:
- a lot of indications on screen where I have to go and what I have to do all at once. I struggled following inscruction but the game is simple so I figured it out
- there is a lot of passivity: other than moving on a bacteria I don't have to do much: it might be interesting adding some sort of evolution. Maybe the macrophage can level up, become faster at eating, eating more than one bacteria at once or having additional actions (for example with space bar it expands and clears briefly a bigger area)

Animations are a little clunky while the macrophage is smooth.

I would dig a little more on the swarm effect of the bacteria: more bacteria, more macrophages coordinates together with you to help with an increasing number of bacteria.

It wasn't clear why I had the "hand" indicator and couldn't use it.

All in all I think I've reached the end by just moving around: the challenge was very low (this isn't bad unless you intended to set the bar high).

If you want to add more storyline I would move from the human-scenario to an alien macrophage in an alien body and this macrophage can evolve over time and it moves accordingly to its evolution (slower but bigger, smaller but faster) 

Do you remember Spore? Well, something like that but less complicated.

Hope this helps!