Its really up to you, the theme is a guide and I'll rate games on how pacifist they are. but if the core mechanic is "dodge the spikes and don't die", prob not ideal. Maybe you can think of a different implementation of "if I collide with something, I need to start again". You can have things to avoid, try be creative. and if its just one bit of your game with spikes, then thats prob okay - its not a core mechanic in that case.