Chair smash bug.
First of all, you can perform the chair smash without pressing the attack button, all you have to do is press the down movement button.
So here's the issue.
How to Replicate:
1.) Press the jump button
2.) Hold the left or right movement button.
3.) Press the up movement button.
4.) Press the down movement button.
In this case, the chair smash does not work.
BUT...
If you repeat the steps above, and press the attack button, the chair smash does work.
So either, make it so you have to press the attack button to do the chair smash all the time, or fix the above bug so all you have to do is press the down movement button to do the chair smash.