These are just little suggestions I have.
I have a much bigger list of suggestions but they're not really ones that would require any community input.

Anyway, on with the show!

I'm pretty sure I've posted a few of these ideas in other threads, but I might stick them all in this thread so more people can read them.

Bombs: There are a few things about bombs that bother me.

1. The current animation seems a little jerky and over the top (literally, in a way). I think it's funny, but that kind of quirkiness won't fit in with the final, polished release of the game. I'd just like to see bombs get a bit more love in the animation department, maybe have them held and charged at the side and then tossed one tile forward, with the bomb making a sound/squeak when it lands.
2. While their high level upgrades are quite good, at lower levels, bombs are almost completely useless. Something needs to change between the two extremes (Level 1 ~ Level 10), make the gap not so huge so that it's still feasible to use them at low levels.

Apart from that, I think bombs are good. They were a bit nerfed but I still like them about the same amount as I like guns.

Guns: Guns, are just too slow. That's really the big thing I have to say. People who prefer to use ranged attacks are seriously gimped in this regard. There needs to be some kind of movement speed modifier or reloading speed reducer, because so many monsters can just take advantage of that second or two you're standing still between shots that they're almost completely pointless to use.
The Alchemer is the most useful gun now, just because the bullets ricochet off everything allowing you to stop or slow down multiple monsters to stop them from laying the smackdown on you.

Swords: They need a much stronger lock-on. Maybe vicinity based instead of cursor directional. I often find swords counter intuitive when it comes to using the lock-on just because you'll hit something twice and the third attack flies past the monster getting you stuck in a corner.
I'm not saying make the game easier by giving everyone easy mode lock-on, but it wouldn't hurt for people to be able to finish a combo on the rare occasion they don't get whomped mid attack and have start all over again.

Furnace: This is a big furnace, it allows you to transfer heat from items to other items, but it destroys the item used to transfer the heat in the process.
Fairly simple concept that will give some use to old gear.
It wouldn't be a 100% heat transfer, 50~70% at the most for items of the same star quality.
Only like items can transfer heat, gun to gun or armour to armour, no sword to armour or shield to gun.

Procedural Recipes: Basically, you get given a list of things you need to do to get the items required to alchemize the item.
Like, maybe to get green shards you need to freeze an enemy and kill them while they're frozen.
Some monsters might only drop certain items (at a fairly high rate) when you have a recipe.
Random material drops for rare, high star gear would still exist and stick around for trade, but I think this would be a good way to take frustration out of crafting, give vials a lot of use for low level materials and just in general make it take that little bit longer, so that people don't have super high quality gear on their first day.
Certain additions to recipes might allow you to get specific enhancements on the crafted item, to take random chance out of the equation.

Heat Allocation: I think people should be able to choose which equipped items get heat.
Heat gain should be reduced to compensate, so that equipment growth is stunted a little on the items.

Gravity: I'd love to see monsters that are dying to go flying over the edge of a cliff into oblivion. Drops for monsters would have to come out before they poof for this to work, but I think it's a small sacrifice for something that cool.
I mean that bottomless pit is just sitting there doing nothing.
As an extension of this, I'd also like to see levels where falling off the edge is possible.

Monster Dodging: I've noticed that when monsters dodge, they go completely invincible. It takes the point out of using a faster weapon when 90% of your attacks hit only for them to not do any damage. This is especially true when using guns, since a lot of faster monsters can dodge sideways along the wall all the way up until they're within striking distance.
It's annoying and while I have nothing against the monsters being smart, letting them go invincible when they dash and dodge is a bit ridiculous, especially when they don't go under the ground or anything.

Chance to Status: I think it should be shown what chance the player has to inflict a status (or if an item has a status if it isn't listed in the description).
Just low, medium, high or extreme as an indicator of the chance, over a number.
I know some items inflict statuses at increasing rates for each hit in a combo, but an indicator can help people build synergy with their equipment.

Extended Statistics: As an extension of my previous idea, a drop down view of what your resistances are in the equipment window would be handy as well. If you didn't have any resistance or weakness to an element, it wouldn't be displayed, to prevent clutter.

That's about all I can think of for now, I might edit in some more stuff later if I think of anything.