Thanks to @mreimerstow for his original project. If you are backpacking this project's scripts or sprites, be sure to give credit to @mreimerstow Please comment any glitches or errors! I will try to fix them. I decided to use the trick using custom made blocks and the "no screen refresh" checkbox.
This is a slightly less glitchy version of the project by @mreimerstow. Also this version prevents horizontal movement through walls and jumping up through the bottom of a platform, but you can get stuck in the ground if you fall from a high enough point. Note that this is not the best platformer sample, as it lacks things such as good wall jumping or slope detection.