This is part of the code I wrote to make a "foolproof" physics engine (meaning there's no way for an object to pass through a block by going too fast). It uses mget to check if a tile is there or not which should be pretty fast although maybe not the fastest. This is based on the blog post by Towerfall creator Matt. Although there's missing features like moving solids and stuff it's inspired by it.
If you haven't read the blog post about this you should, it's quite insightful!
arrows, o to jump normally, x to fly really fast upwards to show that you won't pass through things
at extreme speeds.
Feel free to use this code.