Consider adding a separate audio sliders for each note (maybe in the options menu), because I think the Yellow & Green are too sharp, but currently I can only turn down the volume for all of them. This is my biggest problem with the game, since I have damaged hearing & too loud noise is uncomfortable, so I have to play it too quietly instead.
I would also like a more forgiving damage system, either it's easier to acquire more hearts (from eg: shop/enemy drops/hidden secrets/...), OR being hit by an enemy doesn't consume a whole heart, but only a fraction of a heart, and as long as you haven't lost a whole heart you can still regenerate that lost health (either from not being hit for a while (bad, leads to "coward" tactics), or the "coins" also heals you, or if the enemies also drops health particles in addition to the coins, or you can get "vampiric weapons" that drains health from enemies to you, or you have a "heal ability" on a cool-down timer, or can buy healing in the shop).
You could also add an "ascension mechanic" so dying isn't as "pointless" as it currently is, lets say it lets you save the score (or something) to the next run, and when you have enough saved score it lets buy permanent boosts* that you start with in future re-spawns, (*eg: more white note blocks, or with one of those colored notes (I still don't know what those do?), or start with a (random?) upgrade, or something else).
It could also be interesting if the rooms defied the difficulty, so going Up makes it harder (& eventually you get the boss), sideways keep the current difficultly & Downwards lowers the difficulty.
In this way, the players can decide how hard they want the levels to be :D
(maybe add some "loot reduction multiplier" (max is like -50% loot) if the player have stayed at the same difficulty too long (like 10 levels or so), just to gently encourage the player to actually progress through the game without forcing it).
Also, the "coins" shouldn't de-spawn (maybe as an "ascension perk") until you leave the room, maybe with a "collect all" feature when all enemies are dead.
Ps. I found you game from here:
Hey thanks for the feedback and ideas.
I will put the different colour volume controls down on the to do list.
We might look into starting the player off with more health and upping its spawn chance in shops.
There is a lot more to come with the player progression and unlocking things in the game. We just haven't had the time to get to it yet.
I appreciate all the feedback and I'll take all the ideas into consideration. Thanks!
I agree with sensino on most things, and I have a few ideas of my own;
maybe make it so after each world, you have an option, either a new note, or a new column for notes, that way it slowly becomes more complicated at a manageable rate, allowing you to slowly proogress towards having a massive symphony.
you could possibly make it so that bosses drop heart upgrades, so you go from 3 to 4. this would work well
I really enjoy the concept of special attacks, like the riot shield, it adds a unique spin and keeps it interesting.
this is an amazing game and I cant wait for it to be fully released, it is such a good concept.