Celeste

• It's recommended to play with a d-pad or keyboard as they allow for more precise dashing than an analog stick.

• Don't ragequit, take a break! The game has a quicksave function for a reason. Use it freely.

• Once you beat a level once, you can go back between the sections and see exactly which strawberries you got or missed. All they affect is a small bit of the ending.

• There are higher-difficulty techniques you may have heard about from speedruns. Hyperdashing, spike jumping, etc. Don't worry, the game will teach you those when you need them.

Further Challenges

• Save these for if you start really wanting to dig into the game, or after you've beaten the main game and want more.

• Along with the strawberries, each level also has a hidden tape that lets you get to a harder version of that level, the B-Side. Beating a B-Side gets you a
  Crystal Heart
  , which you will need collect four of if you want to play the
  World 8 A-Side
  .

• A-Sides also each contain a
  Crystal Heart
  , all of which you will need as well if you want to unlock the
  World 7 B-Side
  . These ones are hidden in much more obscure places, however, most of which will require some serious puzzling, observation, and a bit of "huh, I wonder if that would work." (Or you can look it up, I guess.)

• Once you've completed all of that, congratulations, you've earned the right to challenge...
  the C-Sides
  . This is where all those speed running skills you got told not to worry about before become relevance. Good luck.