Again with this style of stuff; when will people learn that it doesn't look good? Yea, graphics don't have to be all super flashy and use multi-color palettes, but these are all the generic stuff someone would expect to see on TTG; try to be more unique. Ditch the scan lines and look for other patterns that create a more appealing look, the shapes are odd on some of them. Not sure if that's a good or bad thing yet. The C4D text is, again, really generic.
I didn't even bother looking at the speed art, but chances are if it's not an extremely good speed painting, it's not even worth looking at. Based on these I'd say you're still a beginner, so my best advice to you is DON'T do speed art until you are A LOT more familiar with the tools you use.
Is it just habit to copy everyone on TTG/GB with these? (honestly wondering this)