I really like such kind of gameplay, a forever runner game with a jumping mechanic. I also enjoyed the pixel art and relaxing background music quite a lot. My suggestion here would be giving some sound feedbacks when player presses space key to jump, maybe just the simplest train whistle sound? Additionally, now the railroad signs are respawned in very evenly position, I think adding or reducing distance between each railroad signs could provide a greater challenge for players. Great work!