I finally got to try this yesterday. Played it for 3 hours straight. By the time I was done I'd already gotten the 1cc, two separate times, but it was really rough at first.
I'm a series vet...the first game remains one of my all-time favs. 1cc-ed both it and 2, many times. Never spent enough time with 3 or 4 to get that good, but enjoyed them nonetheless, even though 4 seemed pretty uninspired.
The dual pedal mechanic is...really fun, actually, and did not take very long to get used to. The graphics are great, except for the occasional stutter--was not prepared for that. Also, the HACS at the end of 1-2 didn't explode at one point...just continued floating there as I walked on by, lol.
The difficulty seemed absolutely brutal at first. I knew that your amount of time to duck after seeing a red circle had dropped for TC4, but it seems to be even less time now. Thing is, the amount of time can vary greatly depending on the enemy's distance from you. During the final battle with Wild Dog, when he is on a moving vehicle some distance away, you actually have way more time to dodge than you do in Stage 1, where all of the enemies are in close proximity. Making matters worse is the fact that most of the attacking enemies attack again very soon after, sometimes less than half a second later, and then again after that. Casual players all got murdered very quickly and most did not bother continuing or trying again. My first few credits also ended very quickly.
Finally I changed my play style and had much more success; instead of waiting for red-shirted enemies to attack, then trying to counterattack, I instead learned their patterns and shot them down before they had a chance to attack. As usual, the non-red enemies seldom attack, so this generally led to safety. Most of the enemies appear in the same places every time, with few exceptions, and the boss battles/minigame events never change (though the "press the indicated pedal quickly!" event chooses randomly between the two, so you can't just fall asleep), so memorizing my way to victory was not difficult.
My final playthrough was completed in 7'02"85. That's the shortest Time Crisis game ever; while I think it was possible to clear the first game in under 10 minutes, you're talking world-record territory there.
The minigame events are entertaining, and there's nothing frustrating/silly like the 3-screen battles from TC4. Overall, it's a lot of fun, and very intense...while it lasts.