Thank you for playing!
Does the movement feel slow outside only or in all of the game? You can find upgrades to increase it; later on once there's more content variety the game will scale more and faster. You cannot attack in the outside room due to the way level completion works at the moment. May allow it, but for now there's only one character either way.
You have to confirm to enter because it's reused from shop doors atm. Transition is highly WIP; one thing I didn't want to do however is connect the rooms or have a "logical" transition, because the game branches: some stages (going by number) can be a different room each time, and there will be extensive branches once it's finished too. Atm you can get some random rooms at some points, and later in the dungeon either one of two branches (you'll notice they have a title on screen) - this is the "groups" in the dungeon editor, by the way.
Similarly the reason you cannot move manually to the next room is that I cannot afford the space to place a door in all the levels, so outside shops it's just more of a decoration. I may make it so there's always a door visible in the future, but it may still not be related to exiting the room. The reasons for that is that it takes time to do so (though arguably for some that may be preferable, but I've already had people saying they want the game to take no breaks) and that it would compromise the layout of the rooms; for example, you couldn't then have a map where you're isolated in the middle.
When you don't have enough money, it says "You cannot offer // What you do not have". Was this not the case? Either way, this is placeholder as the upgrades system will allow for "stealing" in the future.
Variety will improve once I get the time to add more enemies and upgrades, hahah. Obviously the very few present now won't carry the whole game. The second character is a cameo from another AGDG game, and is definitely not meant to be seen as the "proper" way to play the game. I think you should be able to right now, though. Jump with M2 and attack with M1. The combos are written out in the character selection screen.
Thank you for taking your time trying out the editors! In regards to level editor controls, RMB deletes "at" level, meaning if you're holding a tile it will delete tiles (and objects), but holding an object will only allow you to delete objects, and won't reset the tile to the biome's default. The dial selector is optimized for speed, but admittedly you have to get used to it first. I will try my best not to have more than 6-7 items per wheel, as that would get far too annoying indeed. I will maybe look into having a palette, but I think once you get used to the dial, it's quite superfluous.
The bigger tiles and the meadow biome at large are meant to be used for entrance rooms. These are not "gameplay" rooms and benefit from a more organic look. Some "weird" tile transformations exist in order to allow better overlapping of elements in these rooms; for example, the large wall has a ruined bit that extends if it's at the edge of a wall segment. This way, it can merge into dirt walls and slopes more elegantly.
Could you please provide more info in regards to the dungeon editor? It's true that adding and sorting levels is quite jank at the moment, since this editor has definitely not been the focus of the development for now; just making sure it works, which it should. I've not encountered any issues, so I would appreciate any details you can give me.
Eventually, I plan to have a 3d character selection screen where characters you unlock are striking some pose as you suggest. Just not yet! I may also make it so the level clear animation (which doesn't yet exist, if ever) zooms in if playing in singleplayer, but unsure. It may get old quick.