what does the game mean with "the game just got harder"?

[Normanchester]

i finished the game (not for the 10th time) and it gave me the achievement
Maybe its because i literally ONE SHOTTED the boss?

[Well Met]

It's for beating Mom's Heart for the 5th time, more champions/alternate bosses which are usually harder, more curses, less heart drops after boss fights etc. Nothing dramatic. Good luck!

[Normanchester]

Originally posted by Well Met:

It's for beating Mom's Heart for the 5th time, more champions/alternate bosses which are usually harder, more curses, less heart drops after boss fights etc. Nothing dramatic. Good luck!

thanks for the help, im new at the game as you might see for my low knowledge

[Well Met]

Originally posted by Normanchester:

thanks for the help, im new at the game as you might see for my low knowledge

You're welcome, enjoy this great game. Don't worry at all about being new, you'll get it pretty fast, the hardest challenges will still be hard but this game is also super rewarding.

[Big Bird]

Binding of Isaac works like a parabola. There is a increase in difficulty that makes the midgame kinda tough, especially when trying to achieve certain rewards (Unlocking characters/certain items and challenges) but then it goes back to being easy once you start unlocking the broken stuff. Good luck soldier!