So I guess I played the updated version, which is now indeed more challenging. I think it is an interesting idea to have the tradeoff between movement and health, where the player can sacrifice the robot's health in order to more easily reach the boss. I found avoiding the spikes tricky, especially on the third level, but that's ok because these games are meant to be a challenge.
Graphics were simple but clean and the robot character controlled ok (I'd say the full health jump is a bit too weak and the low health jump is a bit too strong, therefore harder to control, medium health jump is good). It would be great to have visual feedback (like particle effects) when the robot gets damaged, since sometimes I thought I didn't get hit and was then surprised when my character moved in a way I didn't expect.