Thanks for the feedback. You're right, it's definitely unfair. You can pretty reliably beat the first level when you're willing to backtrack a little bit, so I don't necessarily see that issue in the first level. In later levels for sure. :D
Having a "smarter" algorithm for spawning spikes would be great. I'm afraid I won't be able to pull that off, though. It's a rage game, so hope it's gonna be fine, but I'll keep an eye on it...