I think what little you have here is pretty engaging, but starting over from the beginning is definitely a pain point that just kills my mood to retry the harder second fight. The lizard boss has 2 burrow-underground-fuck-everyone attacks, but they both share the same animation despite the other one having a much larger radius, if you could make sure each variant has a clear tell, that would go a long way for sure.
I complained about the second boss and the combo system already in the Discord. Definitely looking forward to this once you spend more time working on it.