Scratch

sometimes if you have a lot of sprites, or smooth animations, your game will slow down STACKS. (I just notices this when I tried to make a lighting effect). Here are some ways I dreamed up to keep the FPS up whenever possible.

1. Taking turns to switch costume
The human eye can see at 60 fps, and scratch has goal smoothness of 100 fps. So you don't need to have sprites animating every second. You might only need them to animate about 5 times a second. So that will *theoretically* take out 95% of the lag. But you will still have the frame rate dropping 5% of the time!
Then if you tell certain sprites to wait an amount of time before switching costume, eg, wait 0.05 seconds, then the costumes start switching every 5 seconds, it will keep the framerate consistant, but it can take time to program.

2. Don't make it animate if it is not visible
A useful way to take out unnecesary lag is to not make a sprite animate if it is not visible, this can simply be done by (if distance to object (you) is less than 240, then do whatever animation the sprite would want to do). This will be useful if you are doing a background scroller.

3. Big images eat up FPS when they do stuff
Just make the big image turn into a tiny costume like a dot, and then use let it move. also you can make it not move unless it is visible, by using variables to let it keep track of it's position.

4. Don't make object's 'float' when they aren't in the room.
-floating is when a object highlights when it touches the mouse pointer, this can be ghost effects, colorising, etc...

-what I mean by room is that sometime you are in a main menu, and then you click 'play game' to play the game. Then the broadcasting is done, and you go into a different 'room.'

this is a minor way to speed things up, but sometimes you can be out of the main menu, and although the buttons will be 'hiding,' you can see in the sprites area that their colorising effect is still taking place. You don't want this to happen when you don't even need the buttons, so just make the buttons 'float' when you are in the 'menu' room.

5. Avoid effects if able to do so.
transparency can be made when you put diagonal transparent lines accross the sprite, sometimes this can make it ugly, but do it when you are able to.

other effects such as whirl, pixilate and colorising will take up lots of space and time when you animate them, so don't try to work around these effects!

I hope you found this 'lag-destroyer' tips helpful!