The game is easy to complete and get all the achievements, you just need to get used to the controls.
There are no impassable moments or impossible achievements in the game.
To keep the interest for the passage, important moments will be hidden under spoilers.

During the game, Esc sometimes doesn't work, so it is better to go to the window by pressing F and then close the game.
One of the intros in the game and the final one may be impossible to skip, but even if the keys don't respond, these intros pass after a while.

The character is controlled using the keyboard without a mouse.

Walk: ←, →
Jump: ↑
Crouching: ↓
Move objects: X, C
Kick objects: V
Turn the lever: X

Pressing ↑ twice causes a double jump. To jump further, you need to press the key with a time interval.
Practically in all places of the game is used a double jump, you get used to it and the game goes quickly.
In some places the character can climb on objects, you need to approach them or jump.

Try pushing and kicking things in different places of the location, using this it becomes clear what to do.
There are levers in different places, it's enough to press X once next to them.
The first lever has an animation when pressing X multiple times, it may be related to some achievement.

The clock is in the tunnel with the heart, it works on the same principle as the lever, but for a while: if you didn't have time to get to the platform, then you need to turn on the clock again.
May be related to the achievement - Three o'clock in the morning. For me it opened after the actions with the clock and the finale.

You need to approach two statues, the third one needs to be kicked.
When interacting with the statues, there will be scenes with girls where you can get points.

How to find:

The first statue is in the first location with a stone, you need to kick it and call lightning.
The second statue is on the opposite side from the first lever, you need to kick the statue itself.
You can jump to the third statue from the heart, which is not far from where Beldazy stands, there is an invisible platform.

When meeting vampires without statues, there will be scenes where the character can be absorbed or he arrested them.
The result depends on pressing the buttons, but in any case, after that the character is transported to the moment before the scene.
Leading to the finale is the meeting with Framizza.
To make scenes with vampires available, you need to destroy the hearts.
For achievements, it's better to try different options with each of them.

How to find:

You can get to the first heart, which falls on a hill at the beginning, using a moving platform and a clock.
The second heart is in the tunnel with a clock.
The third heart is near two statues, to drop it you need a box from the place with a spider.

How to destroy:

The first heart is impaled on a pike.
The second touches the third, is dropped to the clock, then moves to the illuminated altar.
The third is moved to the tunnel to the second using platforms.