It kind of bothers me how the environments try so hard to look bust up, while having super straight geometry.
Tilt over some of the stairs' handrail, add a half broken step, make some real geometry dents in the walls (or even just move the vertices a bit) have heaps of fallen plaster.
Make sure the keeper's room has some spiderwebs, a dirty floor, dirty rug, a bunch of small stuff stacked between the box and desk, some dirty work shoes and a shovel somewhere, have the skirting be broken near the hole in the wall, have the hole be an actual hole (alpha the hole and put an inverted box behind it) make the messy and the broken parts match with the rest.
For the exterior, more of the same. Sacrifice 1-2 rocks if you need to stay lowpoly, but get some dings in those concrete walls.
The well picture has less of this geometric look, but I think adding in rocks like that is pretty expensive, compared to
this image which uses a single modular wall part to keep it goodlooking while being lowpoly. The house in your pic is still as straight as an arrow btw. I can understand that you're working modular but that doesn't mean it cant be an
organic looking building.
Clock, table. Nice, but you're using too many polies on the handle thingies. could be spent wiser.
Shotgun would benefit from normal mapping, and the texture looks a bit like stone.
Your menu is very inconsistent. I pressed the word 'gallery' and nothing happened, and later when I pressed your emailadress, again nothing happened. Make all the white lettering links, or all the blue lettering, not a bit of both. Actually, here's a paintover:

You don't need all those 2d pieces, pick the strongest ones, including 1-2 caricatures. You want to do 3d environments or draw exagerrated people?
3d, 2d, demo are pretty straightforward.
resume: make the icons link directly to the word and pdf docs, make the word 'resume' link to a page that has a html resume as well as links to the downloadable docs. This makes it more foolproof (if they'd click and nothing'd happen they'd feel dumb, of think your website was broken)
email would just send an email.
No need for the link to 'more 3d' and the explanation 'there is no 'more 3d' yet'. If you want you can have a message that says you'll upload more, but the button to the nonexistant gallery must go.
Could you please use *.png for the menu, header and footer, instead of *.jpg? text+jpg = ew.