Thank you for your thoughtful review! Yes, distinguishing the bugs from each other when they're up close is intentionally confusing, though it gets a lot easier if you know the combinations by heart after a while.
We actually had a patched version that also features a premature end of the level after killing the bugs, unfortunately it wouldn't let us upload because we missed the deadline by a few minutes. So stay tuned for the improved version right after the jam :P