Very fun game. I love how the timeline system works, and I had a lot of fun plotting and executing a route to get the true ending (though I did have to refer to a guide to find some of the pickups, rather than scouring every corner myself).
Only two complaints, which are that the game doesn't tell you that you can open the gate-puzzle-doors in Drider's lab with a charge shot (I spent way too long trying to find a way to phase through walls or something, since all of them are impossible without knowing this), and it also doesn't tell you that you can super-speed over water, which led to me being stuck until I looked up a guide.