How about adding some games to practice vocabulary? They don't have to be anything too complicated, just simple things like card match, word search, crossword puzzles, word scramble, etc.
Make a 1v1 reasonable speed ping-pong-ish game where you can move the racket with directional arrow keys (only right and left), but in order to 'enable' your racket you must translate a sentence. Right after your adversary hits the ball, 3 short sentences pop up (1 easy, 1 intermediate and 1 hard). You have to quickly translate one, otherwise it is a lost point. The power of your shot will be low if you translate the easy one, whereas if you manage to translate the hard one it will be more powerful, thus giving less time to your adversary. If the game is too slow, it can also be made point-and-click only. For example, you move the racket with the mouse and instead of typing you have to quickly click on some words that fill up the shot power bar.
There's an Australian website I used in early high school when I was learning italian. They have italian, spanish, french, german and a few others but they don't have Portuguese. There are activities starting from super beginner level but its a good addition to duolingo for consolidation.
okay scrap that this is probably only any good if youre just starting out. My bad.
I'm most fond of the crossword puzzle idea! I've done Spanish word searches, card matches, etc. before on other sites and they are boring! The only puzzles I seem to like when practicing other languages are crossword puzzles.