Thanks for the feedback!
First boss has already been nerfed for the final product thanks to some feedback I've already received, I won't be updating the demo but just rest easy knowing that it won't be quite as ridiculous there, the lasers are a lot farther apart now.
Sound effects are something I always seem to forget to work on adding, I can't promise that the sound design will be easy to fix but I might see about it at some point.
The small scythes actually all have the exact same behavior, they just aim based on when they first spawned instead of aiming at where you are now, which makes their behavior somewhat bizarre.
As for the weapon balance, it's... complicated to explain, so bear with me for a bit if you don't mind (I've saved it for last for a reason).
First off, notably, some players have mentioned that they instead opted to exclusively use the boomerang weapon, so I guess some players will opt for one for bosses and some will opt for the other.
Second off, the purple weapon, at a glance, seems to be the best option for every boss. In practice, the boomerang is capable of slightly higher damage output than the purple weapon... as long as it's in constant contact with the boss in question. So against larger bosses, the boomerang is slightly better (at least in theory, been a while since I tested exact numbers on that). Otherwise the purple weapon is. But there's only one large boss in the demo.
The boomerang also has the niche use of collecting health pickups from a distance, which can be very useful in stages sometimes if you're unfortunate enough for an enemy to drop a health pickup out of reach. Which doesn't really happen much in the stages in the demo.
Suffice to say I didn't fully think through the stage choices when it came to showing off the boomerang's capabilities against bosses. To that end I don't really feel like it's a good idea to make adjustments to it yet. If people still have gripes with it in the full game, that's when I'll see about trying re-balancing it.
...as for the ice, yeah, that one is pretty weak against bosses. It's mostly intended as the absolute best option for defeating enemies in the stages, which, well, with how short the stages are... yeah, it's perhaps a bit under-powered, but I'm really not too sure what to do about that without making it too powerful against enemies and/or making it the ideal weapon for bosses instead of the purple weapon by going too far (it's the easiest to use weapon after all).
...the shorter version is, each weapon technically has a niche, but the purple weapon's niche is "does high damage to all bosses", so it's understandable that it's the most immediately obviously useful one. While I'm still not 100% sure on the balance of the weapons, it probably won't change for now to keep another weapon from becoming a legitimately blatantly OP weapon which outright removes the niches of the other two... but I'll think about it.
Sorry about the wall of text to respond to all that... uh, thanks again for the feedback, glad to hear you enjoyed the game overall!