Hey, the game looks great, I'm gonna keep playing, but I just wanted to give a quick, pre-review. I love metroidvanias, and I love the sound of all these special modes, especially the randomiser, which sounds very cool.
One of the first things I notice though, is how hard it is to learn the game. Controls aren't stated in the main game, I didn't even know to use mouse. Feels weird playing a tutorial, and it kind of ruined the surprise of future upgrades. It would be best if these were introduced in the main game, giving you time to learn the powers. I also keep accidentally pressing e, which seems to permanently activate cheat mode. This has killed five runs now, and I'd be very appreciative if this control didn't exist. My final problem is with how clunky this intro feels. Having done five runs, I'm very sick of the slow beginning crawl, having to refill the jetpack, not having any run ability and the slow text. These are a bit of a hinderance; manageable, but perhaps consider making the intro more replayable.
Despite all of that negative stuff, I'm eager to beat it and try out the randomiser (which I guess is the ?! mode?) I like how the game looks and feels, it was just a tad hard to get used to controls.