I focused on a simple mechanic
and I actually like it. I made a twin stick shooter but bullets that go out one side will come back on the other and you can actually should yourself. This accomplishes two things:
- Players who just shoot wildly will endanger themselves and run out of space (Padum! Tsss!)
-You can use this mechanic to kill enemies creatively
Here you can see me using it to make an "ambush"

Also in the special mode your bullets move unpredictable and you are forced to shoot enemies from point blank or have a rogue bullet flying around:

I'm pretty pleased with these mechanics although a lot of other thing can be improved a lot. If you want to try it check : https://ldjam.com/events/ludum-dare/42/changing-spaces