I bought this game last night and became instantly aware of how bad my skill has degraded for 2D precision platforming. I made it to Block Man and got rekt, went to bed and started over again the next day. So far I have beaten Block Man, Blast Man, and Acid Man. I figured Blast Man would have Block Man's weakness and I was right. Thankfully Blast Man's double gear power wasn't as suffocating as Block Man's.
The premise starts with a flashback to Dr. Light and Wily's college years, where Wily's double gear invention was rejected over whatever Dr. Light made. Out of a long game revenge, Dr. Wily arrives at Dr. Light's lab in the present and steals 8 of his robots, completely ignoring Mega Man as one of them, because that makes sense. He turns them evil of course and gives them the Double Gear system. This enhances their ability mid fight, changing up the old formula of out dodge and shoot. Dr. Light gives you the double gear prototype that is trash by comparison... all you can do is get temporary bursts of power or speed based off one meter. If the meter overheats you are locked out of double gear until it cools down. If you're low on health you can use both at the same time to get both benefits at the cost of not being able to cancel it forcing it to go on lockout mode when overheated. Managing this meter is a new wrinkle in the classic Mega Man formula the game generally sticks to. While overheating can be a hassle, enemies will sometimes drop a gear that will speed up your cool down or negate it altogether. Both the speed and power gears use the same cool down meter, so you can't just swap over and get a new meter, it will just finish overheating if you were on the brink before turning it off.
Through out the levels in hard to reach areas and as enemy drops, flashing bolts serve as currency to purchase upgrades for Mega Man, you can buy extra lives, energy tanks, weapon tanks, as basic commodities... I assume you could buy 9000 lives, but it would be sorta a waste. Once you run out of lives, the game over penalty is just having to restart the stage from the start, you don't lose any progress as the old school password system is gone, and loads and saves are in. There are more useful upgrades like faster cool down for the double gear, faster movement speed when the speed gear is active, and spike boots to limit slipping on ice. There are also convenience items like an upgrade that makes picking up refill capsules auto-fill the lowest weapon you have when in base form, beat calls where beat will pick you up out of a hole if you fall, and even an item that halves damage taken during a stage until you die once.
The stages are a mixed bag for me. It still has the typical Mega Man annoyances. Block Man's stage which is in the free demo I believe, has a few sections where a spike column chases you on a conveyor belt while you blast through structures slowing down time at critical moments. Trying to jump up through these stationary maze structures can be tricky as the physics still treat you like your still on the conveyor belt pushing you one way when you're trying to jump up and through a tight spot. They also have the classic "trying to climb up this later, while the screen moves up to the next section, but damn here comes a floaty enemy straight down on me where I can't shoot at him" This can be remedied by slowing down time, but it can still be an annoyance as you have to wait for the first spawn to come down to where you can kill it and try again. And they make sure its on something where if you mess up and still get hit, you get pushed back off the platform and back down to try and climb up again.
The Boss fights themselves can be tough. The double gear mode for these bosses varies. Block Man gets enraged and turns into a giant block monster taking up half the room. You can't jump through or pass him while he ground slams, punches, and throws huge blocks at you. You also can't hit him with your regular buster shots unless he's taking a step or is leaned over a certain way because his critical hit spot is too high to jump to and shoot. When you beat his block monster form, he goes apeshit throwing blocks rapidly at you. What is crazy is when you beat them, along with the flashy circles explosion they scream making it kinda morbid. Especially since they were your friends before all this happened. I'll leave a video below if you want to hear it.