What does "tight space" mean in this context?

Question

I am not sure about the meaning of the word "tight space" in the following sentence in a game's description:

When hungry fishes loom over, tight spaces can be your lifesaver.

The virtual game lets you experience the journey of a fish in deep water.

Please help me confirm which of the following meanings of the word "tight" fits here:

1. Fixed or fastened firmly in place: a tight lid; tight screws; a tight knot.
2. Stretched or drawn out fully: a tight wire; a tight drumhead.
3. Of such close construction as to be impermeable: cloth tight enough to hold water; warm in our tight little cabin.
4. a. Leaving little empty space through compression; compact: a tight suitcase; a tight weave. b. Affording little spare time; full: a tight schedule.
5. Closely reasoned or concise: a tight argument; a tight style of writing.
6. Fitting close or too close to the skin; snug: a tight collar; a fit that was much too tight.
7. Slang Personally close; intimate: "me and the D.A., who happen to be very tight with one another" (Tom Wolfe).
8. Experiencing a feeling of constriction: a tight feeling in the chest.
9. Reluctant to spend or give; stingy.
10. a. Obtainable with difficulty or only at a high price: tight money. b. Affected by scarcity: a tight market.
11. Difficult to deal with or get out of: a tight spot.
12. Barely profitable: a tight bargain.
13. Closely contested; close: a tight match.
14. Chiefly British Neat and trim in appearance or arrangement.
15. Marked by full control over elements or subordinates; firm: tight management; a tight orchestral performance.
16. Slang Intoxicated; drunk.
17. Baseball Inside.

Answer 1

Just to be clear: in this game, you are the fish? And the object is to hide from other, larger fish?

If that's the case, then none of your definitions seem to fit very well. You might try a different dictionary, such as Oxford Living English:

tight (adj): 3. (of an area or space) having or allowing little room for manoeuvre.

In this case, "tight" refers to a small enough space that you can get in, but the larger fish can not.