How to beat AI?

[Emaginary]

I'm getting crushed on just Medium on both Puyo and Tetris. How the hell are you supposed to beat them? Does it matter which character I pick for either mode?

[bentor]

By "Medium" you meant the handicap? Handicap doesn't affect the AI if I'm not wrong... it affects the gameplay.
For example if you choose Sweet(Easy) in Puyo mode, you will have less colors for Puyos, which makes doing chains easier. For Tetris it makes Tetronimos fall slower.

For difficulty, yes. The character you choose for AI matters. Ringo and Tee are the easiest ones. Dark Prince is the hardest one.
If you choose Draco as opponent, she's not going to rotate while playing Puyo mode.

For beating them I'm not quite sure what would help you...

[TheForestSpirit]

You're not the only one. I'm finding it pretty difficult to get into this game I must admit but for me once I start something I like to finish it.

I see so many people giving up at the first hurdle which IMHO is just silly.

[HEU3BECTEH]

I was surprised when I had problems clearing some episodes of story mode. But I did feel I've started to play better when I was able to beat them.
I have more problems beating tetris mode opponents, because they are too good at clearing all the garbage sent to them...

You have bentorianbezil's answer about the difficulty of opponents.
Adding to that, I sort of feel it is easier to beat Sweet-handicapped AI, as it plays slower (not only pieces fall slower, but he moves and rotates them slower too). Not sure about that though.

For me, video-tutorials from YouTube helped:
https://www.youtube.com/watch?v=7MN5bi_EVsY&index=8&list=PLein2LLbDsGo-VGy4MwN-AUCHFXZBUpZX