Thank you for playing my game!
The appearing spikes are made by the shadow enemies. You don't need to jump over those guys.. they can't hurt you, but their spikes CAN hurt you.
I already know about the frozen-spikes bug, but i just didn't had the time to look into it (checking it later... it would take an entier code rewrite of the shadow enemy) but thanks for reporting it.
And also like my menu design, the third level was really rushed, bc i needed time to figure out how to export a game, and then publish it here!
(also.. i think you are the first one who understands really how to play this game :P ).
I hope you enjoyed playing!