The look of this game.

That's exactly how I remember the classic games of yesteryear to look like.

And then you start to play them, and they do not look like this at all... :)

How different is it from, let's say, the Shovel Knight experience? Is it easier than SK?

The most obvious difference would be that this is a metroidvania.

Early impressions:

Game does seem to be structured like a metroidvania; the path so far is sort of linear (I haven't cleared the first area).
You have some basic moves at the start, plus a downward stab.
Vertical scrolling, found in some rooms, is a little odd; the screen only scrolls when you are on the ground (or if you fall).
If you die, you lose 10% of your gold and are sent back to the last checkpoint; this is the only way I've found so far to refill your potion. (I haven't found any shops yet.)
If you quit and reload, you are back at the last checkpoint, with full health but you don't get your potion back.
You start with 3 hearts; your potion restores 2 and has to be used manually; hearts you pick up only restore half a heart.

So far, I am having a bit of difficulty, mainly because of hard to avoid enemies that keep respawning even without leaving the room (think Medusa Heads from Castlevania), and I haven't even reached the first shop, so I can't even spend money to prevent me from losing it. They really should have saved such things for after the first shop.

With that said, there are no bottomless pits. Spikes, so far, do 2 hearts of damage (you start with 3).

There has been one race situation so far, where you have to outrun spikes that are coming down from above. The time limit isn't tight on this section, however (though I don't know about later).

One annoyance when playing under Linux:

If you are using a controller, the game will not prevent the monitor from going to sleep unless you press a key on the keyboard or move the mouse periodically.

To be honest I can see this game becoming the Hollow Knight of 2019 but without the modernized approach to the whole genre.

Its pretty great, however my criticism is that the game itself is early 90s static. Most setpieces like the landscapes seem to be generic. However it also has some ideas borrowed from non-xvania games, such has some things very much alike Shovel Knight, such as the way the player can move the hero around. Very oldschool platformery, more so than other modern metroidvanias.

SOME EXTREMELY MINOR SPOILER INCOMING.

I would give the game a 4/5 for now but I'm a very simple dude. Theres a companion that you gain early on who has a "0w0" face, that alone makes me want to add another whole point to the score.