I already hate the D-pad and I haven't even touched the thing.
The D-pad on the original Evercade Handheld was quite good. This looks like essentially the same D-pad, so that's a good thing in my book.
The face buttons (A, B, X, and Y) appear to be slightly smaller.
The trailer shows that Evercade EXP has four shoulder buttons (L1, L2, R1, and R2), much like the Evercade VS. By comparison, the original handheld only had two shoulder buttons (L and R).
The original handheld's screen resolution was 480x272, the same as the PSP, and approximately 16:9 aspect ratio. The new system is boasting an 800x480 screen, which is a 5:3 ratio, or you can call it 15:9, if you prefer. That's the same aspect ratio as the top screen of the 3DS. It is a slightly less "wide" screen than the PSP or original Evercade Handheld. This shouldn't have any impact on the playability of existing games, as they should all fit within that resolution with ease, but it would affect the borders, which will be drawn differently. They'll probably have some new and updated borders, anyway. The "zoom level" might change for the scaling of some games if they want to maintain "pixel perfect" appearance
and use integer scaling, but I think most of the games will benefit, especially if their original resolution was 320x240 or something very close to that.