I've been playing with Pico-8 for a few days now and love it! Here's my first effort.
The aim of the game is to get the two knights to the big trapdoor (with the key) to escape the level. You control both knights at the same time. The right knight follows your keypresses as you would expect, but the blue knight does the opposite.
I've learnt a lot about Pico-8 while writing this game... mostly what not to do next time. For sure the code could easily be refactored and a lot of duplication removed but thats for another day.
Anyway I hope it gives you a few minutes fun.